Imported Upstream version 1.49.0upstream/1.49.0

1 files changed, 2571 insertions, 0 deletions

diff --git a/boost/wave/util/cpp_iterator.hpp b/boost/wave/util/cpp_iterator.hpp
new file mode 100644
index 0000000000..8441b41faa
--- /dev/null
+++ b/boost/wave/util/cpp_iterator.hpp
@@ -0,0 +1,2571 @@
+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+
+    Definition of the preprocessor iterator
+
+    http://www.boost.org/
+
+    Copyright (c) 2001-2011 Hartmut Kaiser. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+#if !defined(CPP_ITERATOR_HPP_175CA88F_7273_43FA_9039_BCF7459E1F29_INCLUDED)
+#define CPP_ITERATOR_HPP_175CA88F_7273_43FA_9039_BCF7459E1F29_INCLUDED
+
+#include <string>
+#include <vector>
+#include <list>
+#include <cstdlib>
+#include <cctype>
+
+#include <boost/assert.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/filesystem/path.hpp>
+#include <boost/filesystem/operations.hpp>
+#include <boost/spirit/include/classic_multi_pass.hpp>
+#include <boost/spirit/include/classic_parse_tree_utils.hpp>
+
+#include <boost/wave/wave_config.hpp>
+#include <boost/pool/pool_alloc.hpp>
+
+#include <boost/wave/util/insert_whitespace_detection.hpp>
+#include <boost/wave/util/macro_helpers.hpp>
+#include <boost/wave/util/cpp_macromap_utils.hpp>
+#include <boost/wave/util/interpret_pragma.hpp>
+#include <boost/wave/util/transform_iterator.hpp>
+#include <boost/wave/util/functor_input.hpp>
+#include <boost/wave/util/filesystem_compatibility.hpp>
+
+#include <boost/wave/grammars/cpp_grammar_gen.hpp>
+#include <boost/wave/grammars/cpp_expression_grammar_gen.hpp>
+#if BOOST_WAVE_ENABLE_COMMANDLINE_MACROS != 0
+#include <boost/wave/grammars/cpp_predef_macros_gen.hpp>
+#endif
+
+#include <boost/wave/whitespace_handling.hpp>
+#include <boost/wave/cpp_iteration_context.hpp>
+#include <boost/wave/cpp_exceptions.hpp>
+#include <boost/wave/language_support.hpp>
+
+// this must occur after all of the includes and before any code appears
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_PREFIX
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+namespace boost {
+namespace wave {
+namespace util {
+
+///////////////////////////////////////////////////////////////////////////////
+// retrieve the macro name from the parse tree
+template <
+    typename ContextT, typename ParseNodeT, typename TokenT, 
+    typename PositionT
+>
+inline bool  
+retrieve_macroname(ContextT& ctx, ParseNodeT const &node, 
+    boost::spirit::classic::parser_id id, TokenT &macroname, PositionT& act_pos,
+    bool update_position)
+{
+ParseNodeT const *name_node = 0;
+
+    using boost::spirit::classic::find_node;
+    if (!find_node(node, id, &name_node)) 
+    {
+        // ill formed define statement (unexpected, should not happen)
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_define_statement, 
+            "bad parse tree (unexpected)", act_pos);
+        return false;
+    }
+
+typename ParseNodeT::children_t const &children = name_node->children;
+
+    if (0 == children.size() || 
+        children.front().value.begin() == children.front().value.end()) 
+    {
+        // ill formed define statement (unexpected, should not happen)
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_define_statement, 
+            "bad parse tree (unexpected)", act_pos);
+        return false;
+    }
+
+// retrieve the macro name
+    macroname = *children.front().value.begin();
+    if (update_position) {
+        macroname.set_position(act_pos);
+        act_pos.set_column(act_pos.get_column() + macroname.get_value().size());
+    }
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// retrieve the macro parameters or the macro definition from the parse tree
+template <typename ParseNodeT, typename ContainerT, typename PositionT>
+inline bool  
+retrieve_macrodefinition(
+    ParseNodeT const &node, boost::spirit::classic::parser_id id, 
+    ContainerT &macrodefinition, PositionT& act_pos, bool update_position)
+{
+    using namespace boost::wave;
+    typedef typename ParseNodeT::const_tree_iterator const_tree_iterator;
+
+// find macro parameters/macro definition inside the parse tree
+std::pair<const_tree_iterator, const_tree_iterator> nodes;
+
+    using boost::spirit::classic::get_node_range;
+    if (get_node_range(node, id, nodes)) {
+    // copy all parameters to the supplied container
+        typename ContainerT::iterator last_nonwhite = macrodefinition.end();
+        const_tree_iterator end = nodes.second;
+
+        for (const_tree_iterator cit = nodes.first; cit != end; ++cit) {
+            if ((*cit).value.begin() != (*cit).value.end()) {
+            typename ContainerT::iterator inserted = macrodefinition.insert(
+                macrodefinition.end(), *(*cit).value.begin());
+
+                if (!IS_CATEGORY(macrodefinition.back(), WhiteSpaceTokenType) &&
+                    T_NEWLINE != token_id(macrodefinition.back()) &&
+                    T_EOF != token_id(macrodefinition.back()))
+                {
+                    last_nonwhite = inserted;
+                }
+
+                if (update_position) {
+                    (*inserted).set_position(act_pos);
+                    act_pos.set_column(
+                        act_pos.get_column() + (*inserted).get_value().size());
+                }
+            }
+        }
+
+    // trim trailing whitespace (leading whitespace is trimmed by the grammar)
+        if (last_nonwhite != macrodefinition.end()) {
+            if (update_position) {
+                act_pos.set_column((*last_nonwhite).get_position().get_column() +
+                    (*last_nonwhite).get_value().size());
+            }
+            macrodefinition.erase(++last_nonwhite, macrodefinition.end());
+        }
+        return true;
+    }
+    return false;
+}
+
+#if BOOST_WAVE_ENABLE_COMMANDLINE_MACROS != 0
+///////////////////////////////////////////////////////////////////////////////
+//  add an additional predefined macro given by a string (MACRO(x)=definition)
+template <typename ContextT>
+bool add_macro_definition(ContextT &ctx, std::string macrostring,
+    bool is_predefined, boost::wave::language_support language)
+{
+    typedef typename ContextT::token_type token_type;
+    typedef typename ContextT::lexer_type lexer_type;
+    typedef typename token_type::position_type position_type;
+    typedef boost::wave::grammars::predefined_macros_grammar_gen<lexer_type> 
+        predef_macros_type;
+
+    using namespace boost::wave;
+    using namespace std;    // isspace is in std namespace for some systems
+
+// skip leading whitespace
+std::string::iterator begin = macrostring.begin();
+std::string::iterator end = macrostring.end();
+
+    while(begin != end && isspace(*begin))
+        ++begin;
+
+// parse the macro definition
+position_type act_pos("<command line>");
+boost::spirit::classic::tree_parse_info<lexer_type> hit = 
+    predef_macros_type::parse_predefined_macro(
+        lexer_type(begin, end, position_type(), language), lexer_type());
+
+    if (!hit.match || (!hit.full && T_EOF != token_id(*hit.stop))) {
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_macro_definition, 
+            macrostring.c_str(), act_pos);
+        return false;
+    }
+
+// retrieve the macro definition from the parse tree
+token_type macroname;
+std::vector<token_type> macroparameters;
+typename ContextT::token_sequence_type macrodefinition;
+bool has_parameters = false;
+
+    if (!boost::wave::util::retrieve_macroname(ctx, *hit.trees.begin(), 
+            BOOST_WAVE_PLAIN_DEFINE_ID, macroname, act_pos, true))
+        return false;
+    has_parameters = boost::wave::util::retrieve_macrodefinition(*hit.trees.begin(), 
+        BOOST_WAVE_MACRO_PARAMETERS_ID, macroparameters, act_pos, true);
+    boost::wave::util::retrieve_macrodefinition(*hit.trees.begin(), 
+        BOOST_WAVE_MACRO_DEFINITION_ID, macrodefinition, act_pos, true);
+
+//  If no macrodefinition is given, and the macro string does not end with a 
+//  '=', then the macro should be defined with the value '1'
+    if (0 == macrodefinition.size() && 
+        '=' != macrostring[macrostring.size()-1])
+    {
+        macrodefinition.push_back(token_type(T_INTLIT, "1", act_pos));
+    }
+
+// add the new macro to the macromap
+    return ctx.add_macro_definition(macroname, has_parameters, macroparameters, 
+        macrodefinition, is_predefined);
+}
+#endif // BOOST_WAVE_ENABLE_COMMANDLINE_MACROS != 0
+
+///////////////////////////////////////////////////////////////////////////////
+}   // namespace util
+
+///////////////////////////////////////////////////////////////////////////////
+//  forward declaration
+template <typename ContextT> class pp_iterator;
+
+namespace impl {
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  pp_iterator_functor
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+class pp_iterator_functor {
+
+public:
+// interface to the boost::spirit::classic::iterator_policies::functor_input policy
+    typedef typename ContextT::token_type               result_type;
+
+//  eof token
+    static result_type const eof;
+
+private:
+// type of a token sequence
+    typedef typename ContextT::token_sequence_type      token_sequence_type;
+
+    typedef typename ContextT::lexer_type               lexer_type;
+    typedef typename result_type::string_type           string_type;
+    typedef typename result_type::position_type         position_type;
+    typedef boost::wave::grammars::cpp_grammar_gen<lexer_type, token_sequence_type> 
+        cpp_grammar_type;
+
+//  iteration context related types (an iteration context represents a current
+//  position in an included file)
+    typedef base_iteration_context<ContextT, lexer_type>
+        base_iteration_context_type;
+    typedef iteration_context<ContextT, lexer_type> iteration_context_type;
+
+// parse tree related types
+    typedef typename cpp_grammar_type::node_factory_type node_factory_type;
+    typedef boost::spirit::classic::tree_parse_info<lexer_type, node_factory_type> 
+        tree_parse_info_type;
+    typedef boost::spirit::classic::tree_match<lexer_type, node_factory_type> 
+        parse_tree_match_type;
+    typedef typename parse_tree_match_type::node_t       parse_node_type;       // tree_node<node_val_data<> >
+    typedef typename parse_tree_match_type::parse_node_t parse_node_value_type; // node_val_data<>
+    typedef typename parse_tree_match_type::container_t  parse_tree_type;       // parse_node_type::children_t
+
+public:
+    template <typename IteratorT>
+    pp_iterator_functor(ContextT &ctx_, IteratorT const &first_, 
+            IteratorT const &last_, typename ContextT::position_type const &pos_)
+    :   ctx(ctx_), 
+        iter_ctx(new base_iteration_context_type(ctx,
+                lexer_type(first_, last_, pos_, 
+                    boost::wave::enable_prefer_pp_numbers(ctx.get_language())), 
+                lexer_type(), 
+                pos_.get_file().c_str()
+            )), 
+        seen_newline(true), skipped_newline(false), 
+        must_emit_line_directive(false), act_pos(ctx_.get_main_pos()),
+        whitespace(boost::wave::need_insert_whitespace(ctx.get_language()))
+    {
+        act_pos.set_file(pos_.get_file());
+#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
+        ctx_.set_current_filename(pos_.get_file().c_str());
+#endif
+        iter_ctx->emitted_lines = (unsigned int)(-1);   // force #line directive
+    }
+
+// get the next preprocessed token
+    result_type const &operator()();
+
+// get the last recognized token (for error processing etc.)
+    result_type const &current_token() const { return act_token; }
+
+protected:
+    friend class pp_iterator<ContextT>;
+    bool on_include_helper(char const *t, char const *s, bool is_system, 
+        bool include_next);
+
+protected:
+    result_type const &get_next_token();
+    result_type const &pp_token();
+
+    template <typename IteratorT>
+    bool extract_identifier(IteratorT &it);
+    template <typename IteratorT>
+    bool ensure_is_last_on_line(IteratorT& it, bool call_hook = true);
+    template <typename IteratorT>
+    bool skip_to_eol_with_check(IteratorT &it, bool call_hook = true);
+
+    bool pp_directive();
+    template <typename IteratorT>
+    bool handle_pp_directive(IteratorT &it);
+    bool dispatch_directive(tree_parse_info_type const &hit,
+        result_type const& found_directive,
+        token_sequence_type const& found_eoltokens);
+    void replace_undefined_identifiers(token_sequence_type &expanded);
+
+    void on_include(string_type const &s, bool is_system, bool include_next);
+    void on_include(typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end, bool include_next);
+
+    void on_define(parse_node_type const &node);
+    void on_undefine(lexer_type const &it);
+
+    void on_ifdef(result_type const& found_directive, lexer_type const &it);
+//         typename parse_tree_type::const_iterator const &end);
+    void on_ifndef(result_type const& found_directive, lexer_type const& it);
+//         typename parse_tree_type::const_iterator const &end);
+    void on_else();
+    void on_endif();
+    void on_illformed(typename result_type::string_type s);
+
+    void on_line(typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+    void on_if(result_type const& found_directive,
+        typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+    void on_elif(result_type const& found_directive,
+        typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+    void on_error(typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+#if BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0
+    void on_warning(typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+#endif
+    bool on_pragma(typename parse_tree_type::const_iterator const &begin,
+        typename parse_tree_type::const_iterator const &end);
+
+    bool emit_line_directive();
+    bool returned_from_include();
+
+    bool interpret_pragma(token_sequence_type const &pragma_body,
+        token_sequence_type &result);
+
+private:
+    ContextT &ctx;              // context, this iterator is associated with
+    boost::shared_ptr<base_iteration_context_type> iter_ctx;
+
+    bool seen_newline;              // needed for recognizing begin of line
+    bool skipped_newline;           // a newline has been skipped since last one
+    bool must_emit_line_directive;  // must emit a line directive
+    result_type act_token;          // current token
+    typename result_type::position_type &act_pos;   // current fileposition (references the macromap)
+
+    token_sequence_type unput_queue;     // tokens to be preprocessed again
+    token_sequence_type pending_queue;   // tokens already preprocessed
+
+    // detect whether to insert additional whitespace in between two adjacent 
+    // tokens, which otherwise would form a different token type, if 
+    // re-tokenized
+    boost::wave::util::insert_whitespace_detection whitespace; 
+};
+
+///////////////////////////////////////////////////////////////////////////////
+//  eof token
+template <typename ContextT>
+typename pp_iterator_functor<ContextT>::result_type const
+    pp_iterator_functor<ContextT>::eof;
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  returned_from_include()
+// 
+//      Tests if it is necessary to pop the include file context (eof inside
+//      a file was reached). If yes, it pops this context. Preprocessing will
+//      continue with the next outer file scope.
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline bool 
+pp_iterator_functor<ContextT>::returned_from_include()
+{
+    if (iter_ctx->first == iter_ctx->last && ctx.get_iteration_depth() > 0) {
+    // call the include policy trace function
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+        ctx.get_hooks().returning_from_include_file();
+#else
+        ctx.get_hooks().returning_from_include_file(ctx.derived());
+#endif
+
+    // restore the previous iteration context after finishing the preprocessing 
+    // of the included file
+        BOOST_WAVE_STRINGTYPE oldfile = iter_ctx->real_filename;
+        position_type old_pos (act_pos);
+
+    // if this file has include guards handle it as if it had a #pragma once
+#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
+        if (need_include_guard_detection(ctx.get_language())) {
+            std::string guard_name;
+            if (iter_ctx->first.has_include_guards(guard_name))
+                ctx.add_pragma_once_header(ctx.get_current_filename(), guard_name);
+        }
+#endif 
+        iter_ctx = ctx.pop_iteration_context();
+
+        must_emit_line_directive = true;
+        iter_ctx->emitted_lines = (unsigned int)(-1);   // force #line directive
+        seen_newline = true;
+
+    // restore current file position
+        act_pos.set_file(iter_ctx->filename);
+        act_pos.set_line(iter_ctx->line);
+        act_pos.set_column(0);
+
+    // restore the actual current file and directory 
+#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
+        namespace fs = boost::filesystem;
+        fs::path rfp(wave::util::create_path(iter_ctx->real_filename.c_str()));
+        std::string real_filename(rfp.string());
+        ctx.set_current_filename(real_filename.c_str());
+#endif 
+        ctx.set_current_directory(iter_ctx->real_filename.c_str());
+        ctx.set_current_relative_filename(iter_ctx->real_relative_filename.c_str());
+
+    // ensure the integrity of the #if/#endif stack
+    // report unbalanced #if/#endif now to make it possible to recover properly
+        if (iter_ctx->if_block_depth != ctx.get_if_block_depth()) {
+            using boost::wave::util::impl::escape_lit;
+            BOOST_WAVE_STRINGTYPE msg(escape_lit(oldfile));
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, unbalanced_if_endif, 
+                msg.c_str(), old_pos);
+        }
+        return true;
+    }
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  operator()(): get the next preprocessed token
+//
+//      throws a preprocess_exception, if appropriate
+//
+///////////////////////////////////////////////////////////////////////////////
+namespace impl {
+
+    //  It may be necessary to emit a #line directive either 
+    //  - when comments need to be preserved: if the current token is not a 
+    //    whitespace, except comments
+    //  - when comments are to be skipped: if the current token is not a 
+    //    whitespace token.
+    template <typename ContextT> 
+    bool consider_emitting_line_directive(ContextT const& ctx, token_id id)
+    {
+        if (need_preserve_comments(ctx.get_language())) {
+            if (!IS_CATEGORY(id, EOLTokenType) && !IS_CATEGORY(id, EOFTokenType))
+            {
+                return true;
+            }
+        }
+        if (!IS_CATEGORY(id, WhiteSpaceTokenType) && 
+            !IS_CATEGORY(id, EOLTokenType) && !IS_CATEGORY(id, EOFTokenType))
+        {
+          return true;
+        }
+        return false;
+    }
+}
+
+template <typename ContextT> 
+inline typename pp_iterator_functor<ContextT>::result_type const &
+pp_iterator_functor<ContextT>::operator()()
+{
+    using namespace boost::wave;
+
+    // make sure the cwd has been initialized
+    ctx.init_context();
+
+    // loop over skip able whitespace until something significant is found
+    bool was_seen_newline = seen_newline;
+    token_id id = T_UNKNOWN;
+
+    try {   // catch lexer exceptions
+        do {
+        // get_next_token assigns result to act_token member
+            if (skipped_newline)
+                seen_newline = true;
+            get_next_token();
+
+        // if comments shouldn't be preserved replace them with newlines
+            id = token_id(act_token);
+            if (!need_preserve_comments(ctx.get_language()) &&
+                (T_CPPCOMMENT == id || context_policies::util::ccomment_has_newline(act_token)))
+            {
+                act_token.set_token_id(id = T_NEWLINE);
+                act_token.set_value("\n");
+            }
+
+        } while (ctx.get_hooks().may_skip_whitespace(ctx.derived(), act_token, skipped_newline));
+    }
+    catch (boost::wave::cpplexer::lexing_exception const& e) {
+    // dispatch any lexer exceptions to the context hook function
+        ctx.get_hooks().throw_exception(ctx.derived(), e);
+        return act_token;
+    }
+
+// if there were skipped any newlines, we must emit a #line directive
+    if ((must_emit_line_directive || (was_seen_newline && skipped_newline)) && 
+        impl::consider_emitting_line_directive(ctx, id)) 
+    {
+    // must emit a #line directive
+        if (need_emit_line_directives(ctx.get_language()) && emit_line_directive()) 
+        {
+            skipped_newline = false;
+            ctx.get_hooks().may_skip_whitespace(ctx.derived(), act_token, skipped_newline);     // feed ws eater FSM
+            id = token_id(act_token);
+        }
+    }
+
+// cleanup of certain tokens required
+    seen_newline = false;
+    switch (static_cast<unsigned int>(id)) {
+    case T_NONREPLACABLE_IDENTIFIER:
+        act_token.set_token_id(id = T_IDENTIFIER);
+        break;
+
+    case T_GENERATEDNEWLINE:  // was generated by emit_line_directive()
+        act_token.set_token_id(id = T_NEWLINE);
+        ++iter_ctx->emitted_lines;
+        seen_newline = true;
+        break;
+
+    case T_NEWLINE:
+    case T_CPPCOMMENT:
+        seen_newline = true;
+        ++iter_ctx->emitted_lines;
+        break;
+
+#if BOOST_WAVE_SUPPORT_CPP0X != 0
+    case T_RAWSTRINGLIT:
+        iter_ctx->emitted_lines += 
+            context_policies::util::rawstring_count_newlines(act_token);
+        break;
+#endif
+
+    case T_CCOMMENT:          // will come here only if whitespace is preserved
+        iter_ctx->emitted_lines += 
+            context_policies::util::ccomment_count_newlines(act_token);
+        break;
+
+    case T_PP_NUMBER:        // re-tokenize the pp-number
+        {
+            token_sequence_type rescanned;
+
+            std::string pp_number(
+                util::to_string<std::string>(act_token.get_value()));
+
+            lexer_type it = lexer_type(pp_number.begin(), 
+                pp_number.end(), act_token.get_position(), 
+                ctx.get_language());
+            lexer_type end = lexer_type();
+
+            for (/**/; it != end && T_EOF != token_id(*it); ++it) 
+                rescanned.push_back(*it);
+
+            pending_queue.splice(pending_queue.begin(), rescanned);
+            act_token = pending_queue.front();
+            id = token_id(act_token);
+            pending_queue.pop_front();
+        }
+        break;
+
+    case T_EOF:
+        seen_newline = true;
+        break;
+
+    default:    // make sure whitespace at line begin keeps seen_newline status
+        if (IS_CATEGORY(id, WhiteSpaceTokenType))
+            seen_newline = was_seen_newline;
+        break;
+    }
+
+    if (whitespace.must_insert(id, act_token.get_value())) {
+    // must insert some whitespace into the output stream to avoid adjacent
+    // tokens, which would form different (and wrong) tokens
+        whitespace.shift_tokens(T_SPACE);
+        pending_queue.push_front(act_token);        // push this token back
+        return act_token = result_type(T_SPACE, 
+            typename result_type::string_type(" "), 
+            act_token.get_position());
+    }
+    whitespace.shift_tokens(id);
+    return ctx.get_hooks().generated_token(ctx.derived(), act_token);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline typename pp_iterator_functor<ContextT>::result_type const &
+pp_iterator_functor<ContextT>::get_next_token()
+{
+    using namespace boost::wave;
+
+// if there is something in the unput_queue, then return the next token from
+// there (all tokens in the queue are preprocessed already)
+    if (!pending_queue.empty() || !unput_queue.empty()) 
+        return pp_token();      // return next token
+
+// test for EOF, if there is a pending input context, pop it back and continue
+// parsing with it
+bool returned_from_include_file = returned_from_include();
+
+// try to generate the next token 
+    if (iter_ctx->first != iter_ctx->last) {
+        do {
+        // If there are pending tokens in the queue, we'll have to return 
+        // these. This may happen from a #pragma directive, which got replaced
+        // by some token sequence.
+            if (!pending_queue.empty()) {
+            util::on_exit::pop_front<token_sequence_type> 
+                pop_front_token(pending_queue);
+
+                return act_token = pending_queue.front();
+            }
+
+        // adjust the current position (line and column)
+        bool was_seen_newline = seen_newline || returned_from_include_file;
+
+        // fetch the current token
+            act_token = *iter_ctx->first;
+            act_pos = act_token.get_position();
+
+        // act accordingly on the current token
+        token_id id = token_id(act_token);
+
+            if (T_EOF == id) {
+            // returned from an include file, continue with the next token
+                whitespace.shift_tokens(T_EOF);
+                ++iter_ctx->first;
+
+            // now make sure this line has a newline
+                if ((!seen_newline || act_pos.get_column() > 1) && 
+                    !need_single_line(ctx.get_language())) 
+                {
+                // warn, if this file does not end with a newline
+                    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                        last_line_not_terminated, "", act_pos);
+                }
+                continue;   // if this is the main file, the while loop breaks
+            }
+            else if (T_NEWLINE == id || T_CPPCOMMENT == id) {   
+            // a newline is to be returned ASAP, a C++ comment too
+            // (the C++ comment token includes the trailing newline)
+                seen_newline = true;
+                ++iter_ctx->first;
+
+                if (!ctx.get_if_block_status()) {
+                // skip this token because of the disabled #if block
+                    whitespace.shift_tokens(id);  // whitespace controller
+                    util::impl::call_skipped_token_hook(ctx, act_token);
+                    continue;
+                }
+                return act_token; 
+            }
+            seen_newline = false;
+
+            if (was_seen_newline && pp_directive()) {
+            // a pp directive was found
+//                 pending_queue.push_back(result_type(T_NEWLINE, "\n", act_pos));
+//                 seen_newline = true;
+//                 must_emit_line_directive = true;
+
+            // loop to the next token to analyze
+            // simply fall through, since the iterator was already adjusted 
+            // correctly
+            }
+            else if (ctx.get_if_block_status()) {
+            // preprocess this token, eat up more, if appropriate, return 
+            // the next preprocessed token
+                return pp_token();
+            }
+            else {
+            // compilation condition is false: if the current token is a 
+            // newline, account for it, otherwise discard the actual token and 
+            // try the next one
+                if (T_NEWLINE == token_id(act_token)) {
+                    seen_newline = true;
+                    must_emit_line_directive = true;
+                }
+
+            // next token
+                util::impl::call_skipped_token_hook(ctx, act_token);
+                ++iter_ctx->first;
+            }
+
+        } while ((iter_ctx->first != iter_ctx->last) || 
+                 (returned_from_include_file = returned_from_include()));
+
+    // overall eof reached
+        if (ctx.get_if_block_depth() > 0 && !need_single_line(ctx.get_language())) 
+        {
+        // missing endif directive(s)
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                missing_matching_endif, "", act_pos);
+        }
+    }
+    else {
+        act_token = eof;            // this is the last token
+    }
+
+//  whitespace.shift_tokens(T_EOF);     // whitespace controller
+    return act_token;                   // return eof token
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  emit_line_directive(): emits a line directive from the act_token data
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline bool
+pp_iterator_functor<ContextT>::emit_line_directive()
+{
+    using namespace boost::wave;
+
+typename ContextT::position_type pos = act_token.get_position();
+
+//     if (must_emit_line_directive && 
+//         iter_ctx->emitted_lines+1 == act_pos.get_line() &&
+//         iter_ctx->filename == act_pos.get_file())
+//     {
+//         must_emit_line_directive = false;
+//         return false;
+//     }
+
+    if (must_emit_line_directive || 
+        iter_ctx->emitted_lines+1 != act_pos.get_line()) 
+    {
+    // unput the current token
+        pending_queue.push_front(act_token);
+        pos.set_line(act_pos.get_line());
+
+        if (iter_ctx->emitted_lines+2 == act_pos.get_line()) {
+        // prefer to output a single newline instead of the #line directive
+//             whitespace.shift_tokens(T_NEWLINE);
+            act_token = result_type(T_NEWLINE, "\n", pos);
+        }
+        else {
+        // account for the newline emitted here
+            act_pos.set_line(act_pos.get_line()-1);
+            iter_ctx->emitted_lines = act_pos.get_line()-1;
+
+        token_sequence_type pending;
+
+            if (!ctx.get_hooks().emit_line_directive(ctx, pending, act_token))
+            {
+            unsigned int column = 6;
+
+                // the hook did not generate anything, emit default #line
+                pos.set_column(1);
+                pending.push_back(result_type(T_PP_LINE, "#line", pos));
+
+                pos.set_column(column);      // account for '#line'
+                pending.push_back(result_type(T_SPACE, " ", pos));
+
+            // 21 is the max required size for a 64 bit integer represented as a 
+            // string
+            char buffer[22];
+
+                using namespace std;    // for some systems sprintf is in namespace std
+                sprintf (buffer, "%d", pos.get_line());
+
+                pos.set_column(++column);                 // account for ' '
+                pending.push_back(result_type(T_INTLIT, buffer, pos));
+                pos.set_column(column += (unsigned int)strlen(buffer)); // account for <number>
+                pending.push_back(result_type(T_SPACE, " ", pos));
+                pos.set_column(++column);                 // account for ' '
+
+            std::string file("\"");
+            boost::filesystem::path filename(
+                wave::util::create_path(act_pos.get_file().c_str()));
+
+                using wave::util::impl::escape_lit;
+                file += escape_lit(wave::util::native_file_string(filename)) + "\"";
+
+                pending.push_back(result_type(T_STRINGLIT, file.c_str(), pos));
+                pos.set_column(column += (unsigned int)file.size());    // account for filename
+                pending.push_back(result_type(T_GENERATEDNEWLINE, "\n", pos));
+            }
+
+        // if there is some replacement text, insert it into the pending queue
+            if (!pending.empty()) {
+                pending_queue.splice(pending_queue.begin(), pending);
+                act_token = pending_queue.front();
+                pending_queue.pop_front();
+            }
+        }
+
+        must_emit_line_directive = false;     // we are now in sync
+        return true;
+    }
+
+    must_emit_line_directive = false;         // we are now in sync
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  pptoken(): return the next preprocessed token
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline typename pp_iterator_functor<ContextT>::result_type const &
+pp_iterator_functor<ContextT>::pp_token()
+{
+    using namespace boost::wave;
+
+token_id id = token_id(*iter_ctx->first);
+
+    // eat all T_PLACEHOLDER tokens, eventually slipped through out of the
+    // macro engine
+    do { 
+        if (!pending_queue.empty()) {
+        // if there are pending tokens in the queue, return the first one
+            act_token = pending_queue.front();
+            pending_queue.pop_front();
+            act_pos = act_token.get_position();
+        }
+        else if (!unput_queue.empty()
+              || T_IDENTIFIER == id 
+              || IS_CATEGORY(id, KeywordTokenType)
+              || IS_EXTCATEGORY(id, OperatorTokenType|AltExtTokenType)
+              || IS_CATEGORY(id, BoolLiteralTokenType))
+        {
+        //  call the lexer, preprocess the required number of tokens, put them
+        //  into the unput queue
+            act_token = ctx.expand_tokensequence(iter_ctx->first, 
+                iter_ctx->last, pending_queue, unput_queue, skipped_newline);
+        }
+        else {
+        // simply return the next token
+            act_token = *iter_ctx->first;
+            ++iter_ctx->first;
+        }
+        id = token_id(act_token);
+
+    } while (T_PLACEHOLDER == id);
+    return act_token;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  pp_directive(): recognize a preprocessor directive
+//
+///////////////////////////////////////////////////////////////////////////////
+namespace impl {
+
+    // call 'found_directive' preprocessing hook
+    template <typename ContextT>
+    bool call_found_directive_hook(ContextT& ctx, 
+        typename ContextT::token_type const& found_directive)
+    {
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+        ctx.get_hooks().found_directive(found_directive);     
+#else
+        if (ctx.get_hooks().found_directive(ctx.derived(), found_directive))
+            return true;    // skip this directive and return newline only
+#endif
+        return false;
+    }
+
+//     // call 'skipped_token' preprocessing hook
+//     template <typename ContextT>
+//     void call_skipped_token_hook(ContextT& ctx, 
+//         typename ContextT::token_type const& skipped)
+//     {
+// #if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+//         ctx.get_hooks().skipped_token(skipped);     
+// #else
+//         ctx.get_hooks().skipped_token(ctx.derived(), skipped);
+// #endif
+//     }
+
+    template <typename ContextT, typename IteratorT>
+    bool next_token_is_pp_directive(ContextT &ctx, IteratorT &it, IteratorT const &end)
+    {
+        using namespace boost::wave;
+
+        token_id id = T_UNKNOWN;
+        for (/**/; it != end; ++it) {
+            id = token_id(*it);
+            if (!IS_CATEGORY(id, WhiteSpaceTokenType))
+                break;          // skip leading whitespace
+            if (IS_CATEGORY(id, EOLTokenType) || IS_CATEGORY(id, EOFTokenType))
+                break;          // do not enter a new line
+            if (T_CPPCOMMENT == id ||
+                context_policies::util::ccomment_has_newline(*it)) 
+            {
+                break;
+            }
+
+            // this token gets skipped
+            util::impl::call_skipped_token_hook(ctx, *it);
+        }
+        BOOST_ASSERT(it == end || id != T_UNKNOWN);
+        return it != end && IS_CATEGORY(id, PPTokenType);
+    }
+
+    // verify that there isn't anything significant left on the line
+    template <typename ContextT, typename IteratorT>
+    bool pp_is_last_on_line(ContextT &ctx, IteratorT &it, IteratorT const &end,
+        bool call_hook = true)
+    {
+        using namespace boost::wave;
+
+        // this token gets skipped
+        if (call_hook)
+            util::impl::call_skipped_token_hook(ctx, *it);
+
+        for (++it; it != end; ++it) {
+        token_id id = token_id(*it);
+
+            if (T_CPPCOMMENT == id || T_NEWLINE == id ||
+                context_policies::util::ccomment_has_newline(*it)) 
+            {
+                if (call_hook)
+                    util::impl::call_skipped_token_hook(ctx, *it);
+                ++it;           // skip eol/C/C++ comment
+                return true;    // no more significant tokens on this line
+            }
+
+            if (!IS_CATEGORY(id, WhiteSpaceTokenType))
+                break;
+
+            // this token gets skipped
+            if (call_hook)
+                util::impl::call_skipped_token_hook(ctx, *it);
+        }
+        return false;
+    }
+
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename ContextT, typename IteratorT>
+    bool skip_to_eol(ContextT &ctx, IteratorT &it, IteratorT const &end, 
+        bool call_hook = true)
+    {
+        using namespace boost::wave;
+
+        for (/**/; it != end; ++it) {
+        token_id id = token_id(*it);
+
+            if (T_CPPCOMMENT == id || T_NEWLINE == id ||
+                context_policies::util::ccomment_has_newline(*it)) 
+            {
+                // always call hook for eol 
+                util::impl::call_skipped_token_hook(ctx, *it);
+                ++it;           // skip eol/C/C++ comment
+                return true;    // found eol
+            }
+
+            if (call_hook)
+                util::impl::call_skipped_token_hook(ctx, *it);
+        }
+        return false;
+    }
+
+    ///////////////////////////////////////////////////////////////////////////
+    template <typename ContextT, typename ContainerT>
+    inline void
+    remove_leading_whitespace(ContextT &ctx, ContainerT& c, bool call_hook = true)
+    {
+        typename ContainerT::iterator it = c.begin();
+        while (IS_CATEGORY(*it, WhiteSpaceTokenType)) {
+            typename ContainerT::iterator save = it++;
+            if (call_hook)
+                util::impl::call_skipped_token_hook(ctx, *save);
+            c.erase(save);
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT>
+template <typename IteratorT>
+inline bool 
+pp_iterator_functor<ContextT>::extract_identifier(IteratorT &it)
+{
+    token_id id = util::impl::skip_whitespace(it, iter_ctx->last);
+    if (T_IDENTIFIER == id || IS_CATEGORY(id, KeywordTokenType) || 
+        IS_EXTCATEGORY(id, OperatorTokenType|AltExtTokenType) || 
+        IS_CATEGORY(id, BoolLiteralTokenType))
+    {
+        IteratorT save = it;
+        if (impl::pp_is_last_on_line(ctx, save, iter_ctx->last, false))
+            return true;
+    }
+
+    // report the ill formed directive
+    impl::skip_to_eol(ctx, it, iter_ctx->last);
+
+string_type str(util::impl::as_string<string_type>(iter_ctx->first, it));
+
+    seen_newline = true;
+    iter_ctx->first = it;
+    on_illformed(str);
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT>
+template <typename IteratorT>
+inline bool 
+pp_iterator_functor<ContextT>::ensure_is_last_on_line(IteratorT& it, bool call_hook)
+{
+    if (!impl::pp_is_last_on_line(ctx, it, iter_ctx->last, call_hook)) 
+    {
+    // enable error recovery (start over with the next line)
+        impl::skip_to_eol(ctx, it, iter_ctx->last);
+
+    string_type str(util::impl::as_string<string_type>(
+        iter_ctx->first, it));
+
+        seen_newline = true;
+        iter_ctx->first = it;
+
+    // report an invalid directive
+        on_illformed(str);
+        return false;
+    }
+
+    if (it == iter_ctx->last && !need_single_line(ctx.get_language())) 
+    {
+    // The line doesn't end with an eol but eof token.
+        seen_newline = true;    // allow to resume after warning
+        iter_ctx->first = it;
+
+    // Trigger a warning that the last line was not terminated with a 
+    // newline.
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+            last_line_not_terminated, "", act_pos);
+
+        return false;
+    }
+    return true;
+}
+
+template <typename ContextT>
+template <typename IteratorT>
+inline bool 
+pp_iterator_functor<ContextT>::skip_to_eol_with_check(IteratorT &it, bool call_hook)
+{
+    typename ContextT::string_type value ((*it).get_value());
+    if (!impl::skip_to_eol(ctx, it, iter_ctx->last, call_hook) &&
+        !need_single_line(ctx.get_language())) 
+    {
+    // The line doesn't end with an eol but eof token.
+        seen_newline = true;    // allow to resume after warning
+        iter_ctx->first = it;
+
+    // Trigger a warning, that the last line was not terminated with a 
+    // newline.
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+            last_line_not_terminated, "", act_pos);
+        return false;
+    }
+
+// normal line ending reached, adjust iterator and flag
+    seen_newline = true;
+    iter_ctx->first = it;
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  handle_pp_directive: handle certain pp_directives 
+template <typename ContextT> 
+template <typename IteratorT>
+inline bool
+pp_iterator_functor<ContextT>::handle_pp_directive(IteratorT &it)
+{
+    token_id id = token_id(*it);
+    bool can_exit = true;
+    bool call_hook_in_skip = true;
+    if (!ctx.get_if_block_status()) {
+        if (IS_EXTCATEGORY(*it, PPConditionalTokenType)) {
+        // simulate the if block hierarchy
+            switch (static_cast<unsigned int>(id)) {
+            case T_PP_IFDEF:        // #ifdef
+            case T_PP_IFNDEF:       // #ifndef
+            case T_PP_IF:           // #if
+                ctx.enter_if_block(false);
+                break;
+
+            case T_PP_ELIF:         // #elif
+                if (!ctx.get_enclosing_if_block_status()) {
+                    if (!ctx.enter_elif_block(false)) { 
+                    // #else without matching #if
+                        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                            missing_matching_if, "#elif", act_pos);
+                        return true;  // do not analyze this directive any further
+                    }
+                }
+                else {
+                    can_exit = false;   // #elif is not always safe to skip
+                }
+                break;
+
+            case T_PP_ELSE:         // #else
+            case T_PP_ENDIF:        // #endif
+                {
+                // handle this directive
+                    if (T_PP_ELSE == token_id(*it))
+                        on_else();
+                    else
+                        on_endif();
+
+                // make sure, there are no (non-whitespace) tokens left on 
+                // this line
+                    ensure_is_last_on_line(it);
+
+                // we skipped to the end of this line already
+                    seen_newline = true;
+                    iter_ctx->first = it;
+                }
+                return true;
+
+            default:                // #something else
+                on_illformed((*it).get_value());
+                break;
+            }
+        }
+        else {
+            util::impl::call_skipped_token_hook(ctx, *it);
+            ++it;
+        }
+    }
+    else {
+    // try to handle the simple pp directives without parsing
+        result_type directive = *it;
+        bool include_next = false;
+        switch (static_cast<unsigned int>(id)) {
+        case T_PP_QHEADER:        // #include "..."
+#if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+        case T_PP_QHEADER_NEXT:
+#endif
+            include_next = (T_PP_QHEADER_NEXT == id) ? true : false;
+            if (!impl::call_found_directive_hook(ctx, *it)) 
+            {
+                string_type dir((*it).get_value());
+
+            // make sure, there are no (non-whitespace) tokens left on 
+            // this line
+                if (ensure_is_last_on_line(it))
+                {
+                    seen_newline = true;
+                    iter_ctx->first = it;
+                    on_include (dir, false, include_next);
+                }
+                return true;
+            }
+            break;
+
+        case T_PP_HHEADER:        // #include <...>
+#if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+        case T_PP_HHEADER_NEXT:
+#endif
+            include_next = (T_PP_HHEADER_NEXT == id) ? true : false;
+            if (!impl::call_found_directive_hook(ctx, *it)) 
+            {
+                string_type dir((*it).get_value());
+
+            // make sure, there are no (non-whitespace) tokens left on 
+            // this line
+                if (ensure_is_last_on_line(it))
+                {
+                    seen_newline = true;
+                    iter_ctx->first = it;
+                    on_include (dir, true, include_next);
+                }
+                return true;
+            }
+            break;
+
+        case T_PP_ELSE:         // #else
+        case T_PP_ENDIF:        // #endif
+            if (!impl::call_found_directive_hook(ctx, *it))
+            {
+                // handle this directive
+                if (T_PP_ELSE == token_id(*it))
+                    on_else();
+                else
+                    on_endif();
+
+            // make sure, there are no (non-whitespace) tokens left on 
+            // this line
+                ensure_is_last_on_line(it);
+
+            // we skipped to the end of this line already
+                seen_newline = true;
+                iter_ctx->first = it;
+                return true;
+            }
+            break;
+
+        // extract everything on this line as arguments
+//         case T_PP_IF:                   // #if
+//         case T_PP_ELIF:                 // #elif
+//         case T_PP_ERROR:                // #error
+//         case T_PP_WARNING:              // #warning
+//         case T_PP_PRAGMA:               // #pragma
+//         case T_PP_LINE:                 // #line
+//             break;
+
+        // extract first non-whitespace token as argument
+        case T_PP_UNDEF:                // #undef
+            if (!impl::call_found_directive_hook(ctx, *it) && 
+                extract_identifier(it)) 
+            {
+                on_undefine(it);
+            }
+            call_hook_in_skip = false;
+            break;
+
+        case T_PP_IFDEF:                // #ifdef
+            if (!impl::call_found_directive_hook(ctx, *it) && 
+                extract_identifier(it)) 
+            {
+                on_ifdef(directive, it);
+            }
+            call_hook_in_skip = false;
+            break;
+
+        case T_PP_IFNDEF:               // #ifndef
+            if (!impl::call_found_directive_hook(ctx, *it) && 
+                extract_identifier(it)) 
+            {
+                on_ifndef(directive, it);
+            }
+            call_hook_in_skip = false;
+            break;
+
+#if BOOST_WAVE_SUPPORT_MS_EXTENSIONS != 0
+//         case T_MSEXT_PP_REGION:         // #region ...
+//             break;
+//             
+//         case T_MSEXT_PP_ENDREGION:      // #endregion 
+//             break;
+#endif
+
+        default:
+            can_exit = false;
+            break;
+        }
+    }
+
+// start over with the next line, if only possible
+    if (can_exit) {
+        skip_to_eol_with_check(it, call_hook_in_skip);
+        return true;    // may be safely ignored
+    }
+    return false;   // do not ignore this pp directive
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  pp_directive(): recognize a preprocessor directive
+template <typename ContextT> 
+inline bool
+pp_iterator_functor<ContextT>::pp_directive()
+{
+    using namespace cpplexer;
+
+// test, if the next non-whitespace token is a pp directive
+lexer_type it = iter_ctx->first;
+
+    if (!impl::next_token_is_pp_directive(ctx, it, iter_ctx->last)) {
+    // skip null pp directive (no need to do it via the parser)
+        if (it != iter_ctx->last && T_POUND == BASE_TOKEN(token_id(*it))) {
+            if (impl::pp_is_last_on_line(ctx, it, iter_ctx->last)) {
+            // start over with the next line
+                seen_newline = true;
+                iter_ctx->first = it;
+                return true;
+            }
+            else if (ctx.get_if_block_status()) {
+            // report invalid pp directive
+                impl::skip_to_eol(ctx, it, iter_ctx->last);
+                seen_newline = true;
+
+                string_type str(boost::wave::util::impl::as_string<string_type>(
+                    iter_ctx->first, it));
+
+            token_sequence_type faulty_line;
+
+                for (/**/; iter_ctx->first != it; ++iter_ctx->first)
+                    faulty_line.push_back(*iter_ctx->first);
+
+                token_sequence_type pending;
+                if (ctx.get_hooks().found_unknown_directive(ctx, faulty_line, pending))
+                {
+                // if there is some replacement text, insert it into the pending queue
+                    if (!pending.empty())
+                        pending_queue.splice(pending_queue.begin(), pending);
+                    return true;
+                }
+
+                // default behavior is to throw an exception
+                on_illformed(str);
+            }
+        }
+
+    // this line does not contain a pp directive, so simply return
+        return false;
+    }
+
+// found eof
+    if (it == iter_ctx->last)
+        return false;
+
+// ignore/handle all pp directives not related to conditional compilation while
+// if block status is false
+    if (handle_pp_directive(it)) {
+        // we may skip pp directives only if the current if block status is 
+        // false or if it was a #include directive we could handle directly
+        return true;    //  the pp directive has been handled/skipped
+    }
+
+// found a pp directive, so try to identify it, start with the pp_token
+bool found_eof = false;
+result_type found_directive;
+token_sequence_type found_eoltokens;
+
+tree_parse_info_type hit = cpp_grammar_type::parse_cpp_grammar(
+    it, iter_ctx->last, act_pos, found_eof, found_directive, found_eoltokens);
+
+    if (hit.match) {
+    // position the iterator past the matched sequence to allow 
+    // resynchronization, if an error occurs
+        iter_ctx->first = hit.stop;
+        seen_newline = true;
+        must_emit_line_directive = true;
+
+    // found a valid pp directive, dispatch to the correct function to handle 
+    // the found pp directive
+    bool result = dispatch_directive (hit, found_directive, found_eoltokens);
+
+        if (found_eof && !need_single_line(ctx.get_language())) {
+        // The line was terminated with an end of file token.
+        // So trigger a warning, that the last line was not terminated with a 
+        // newline.
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                last_line_not_terminated, "", act_pos);
+        }
+        return result;
+    }
+    else if (token_id(found_directive) != T_EOF) {
+    // recognized invalid directive
+        impl::skip_to_eol(ctx, it, iter_ctx->last);
+        seen_newline = true;
+
+        string_type str(boost::wave::util::impl::as_string<string_type>(
+            iter_ctx->first, it));
+        iter_ctx->first = it;
+
+    // report the ill formed directive
+        on_illformed(str);
+    }
+    return false;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+//  dispatch_directive(): dispatch a recognized preprocessor directive
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline bool
+pp_iterator_functor<ContextT>::dispatch_directive(
+    tree_parse_info_type const &hit, result_type const& found_directive,
+    token_sequence_type const& found_eoltokens)
+{
+    using namespace cpplexer;
+
+    typedef typename parse_tree_type::const_iterator const_child_iterator_t;
+
+// this iterator points to the root node of the parse tree
+const_child_iterator_t begin = hit.trees.begin();
+
+// decide, which preprocessor directive was found
+parse_tree_type const &root = (*begin).children;
+parse_node_value_type const &nodeval = get_first_leaf(*root.begin()).value;
+//long node_id = nodeval.id().to_long();
+
+const_child_iterator_t begin_child_it = (*root.begin()).children.begin();
+const_child_iterator_t end_child_it = (*root.begin()).children.end();
+
+token_id id = token_id(found_directive);
+
+    // call preprocessing hook
+    if (impl::call_found_directive_hook(ctx, found_directive)) 
+        return true;    // skip this directive and return newline only
+
+    switch (static_cast<unsigned int>(id)) {
+//     case T_PP_QHEADER:      // #include "..."
+// #if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+//     case T_PP_QHEADER_NEXT: // #include_next "..."
+// #endif 
+//         on_include ((*nodeval.begin()).get_value(), false, 
+//             T_PP_QHEADER_NEXT == id);
+//         break;
+
+//     case T_PP_HHEADER:      // #include <...>
+// #if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+//     case T_PP_HHEADER_NEXT: // #include_next <...>
+// #endif 
+//         on_include ((*nodeval.begin()).get_value(), true, 
+//             T_PP_HHEADER_NEXT == id);
+//         break;
+    
+    case T_PP_INCLUDE:      // #include ...
+#if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+    case T_PP_INCLUDE_NEXT: // #include_next ...
+#endif 
+        on_include (begin_child_it, end_child_it, T_PP_INCLUDE_NEXT == id);
+        break;
+
+    case T_PP_DEFINE:       // #define
+        on_define (*begin);
+        break;
+
+//     case T_PP_UNDEF:        // #undef
+//         on_undefine(*nodeval.begin());
+//         break;
+// 
+//     case T_PP_IFDEF:        // #ifdef
+//         on_ifdef(found_directive, begin_child_it, end_child_it);
+//         break;
+// 
+//     case T_PP_IFNDEF:       // #ifndef
+//         on_ifndef(found_directive, begin_child_it, end_child_it);
+//         break;
+
+    case T_PP_IF:           // #if
+        on_if(found_directive, begin_child_it, end_child_it);
+        break;
+
+    case T_PP_ELIF:         // #elif
+        on_elif(found_directive, begin_child_it, end_child_it);
+        break;
+
+//     case T_PP_ELSE:         // #else
+//         on_else();
+//         break;
+
+//     case T_PP_ENDIF:        // #endif
+//         on_endif();
+//         break;
+
+    case T_PP_LINE:         // #line
+        on_line(begin_child_it, end_child_it);
+        break;
+
+    case T_PP_ERROR:        // #error
+        on_error(begin_child_it, end_child_it);
+        break;
+
+#if BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0
+    case T_PP_WARNING:      // #warning
+        on_warning(begin_child_it, end_child_it);
+        break;
+#endif 
+
+    case T_PP_PRAGMA:       // #pragma
+        return on_pragma(begin_child_it, end_child_it);
+
+#if BOOST_WAVE_SUPPORT_MS_EXTENSIONS != 0
+    case T_MSEXT_PP_REGION:
+    case T_MSEXT_PP_ENDREGION:
+        break;              // ignore these
+#endif
+
+    default:                // #something else
+        on_illformed((*nodeval.begin()).get_value());
+        
+        // if we end up here, we have been instructed to ignore the error, so 
+        // we simply copy the whole construct to the output
+        {
+            token_sequence_type expanded;
+            get_token_value<result_type, parse_node_type> get_value;
+
+            std::copy(make_ref_transform_iterator(begin_child_it, get_value), 
+                make_ref_transform_iterator(end_child_it, get_value),
+                std::inserter(expanded, expanded.end()));
+            pending_queue.splice(pending_queue.begin(), expanded);
+        }
+        break;
+    }
+
+    // properly skip trailing newline for all directives
+    typename token_sequence_type::const_iterator eol = found_eoltokens.begin();
+    impl::skip_to_eol(ctx, eol, found_eoltokens.end());
+    return true;    // return newline only
+}
+
+///////////////////////////////////////////////////////////////////////////////
+// 
+//  on_include: handle #include <...> or #include "..." directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_include (string_type const &s, 
+    bool is_system, bool include_next) 
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// strip quotes first, extract filename
+typename string_type::size_type pos_end = s.find_last_of(is_system ? '>' : '\"');
+
+    if (string_type::npos == pos_end) {
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_include_statement, 
+            s.c_str(), act_pos);
+        return;
+    }
+
+typename string_type::size_type pos_begin = 
+    s.find_last_of(is_system ? '<' : '\"', pos_end-1);
+
+    if (string_type::npos == pos_begin) {
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_include_statement, 
+            s.c_str(), act_pos);
+        return;
+    }
+
+std::string file_token(s.substr(pos_begin, pos_end-pos_begin+1).c_str());
+std::string file_path(s.substr(pos_begin+1, pos_end-pos_begin-1).c_str());
+
+// finally include the file
+    on_include_helper(file_token.c_str(), file_path.c_str(), is_system, 
+        include_next);
+}
+
+template <typename ContextT> 
+inline bool  
+pp_iterator_functor<ContextT>::on_include_helper (char const *f, char const *s, 
+    bool is_system, bool include_next) 
+{
+    namespace fs = boost::filesystem;
+
+// try to locate the given file, searching through the include path lists
+std::string file_path(s);
+std::string dir_path;
+#if BOOST_WAVE_SUPPORT_INCLUDE_NEXT != 0
+char const *current_name = include_next ? iter_ctx->real_filename.c_str() : 0;
+#else
+char const *current_name = 0;   // never try to match current file name
+#endif
+
+// call the 'found_include_directive' hook function
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+    ctx.get_hooks().found_include_directive(f, include_next);
+#else
+    if (ctx.get_hooks().found_include_directive(ctx.derived(), f, include_next))
+        return true;    // client returned false: skip file to include 
+#endif
+
+    file_path = util::impl::unescape_lit(file_path);
+    std::string native_path_str;
+
+    if (!ctx.get_hooks().locate_include_file(ctx, file_path, is_system, 
+            current_name, dir_path, native_path_str)) 
+    {
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_include_file, 
+            file_path.c_str(), act_pos);
+        return false;
+    }
+
+// test, if this file is known through a #pragma once directive
+#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
+    if (!ctx.has_pragma_once(native_path_str)) 
+#endif 
+    {
+    // the new include file determines the actual current directory
+        ctx.set_current_directory(native_path_str.c_str());
+
+    // preprocess the opened file
+    boost::shared_ptr<base_iteration_context_type> new_iter_ctx (
+        new iteration_context_type(ctx, native_path_str.c_str(), act_pos, 
+            boost::wave::enable_prefer_pp_numbers(ctx.get_language()),
+            is_system ? base_iteration_context_type::system_header :
+                base_iteration_context_type::user_header));
+
+    // call the include policy trace function
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+        ctx.get_hooks().opened_include_file(dir_path, file_path,
+            ctx.get_iteration_depth(), is_system);
+#else
+        ctx.get_hooks().opened_include_file(ctx.derived(), dir_path, file_path,
+            is_system);
+#endif
+
+    // store current file position
+        iter_ctx->real_relative_filename = ctx.get_current_relative_filename().c_str();
+        iter_ctx->filename = act_pos.get_file();
+        iter_ctx->line = act_pos.get_line();
+        iter_ctx->if_block_depth = ctx.get_if_block_depth();
+        iter_ctx->emitted_lines = (unsigned int)(-1);   // force #line directive
+
+    // push the old iteration context onto the stack and continue with the new
+        ctx.push_iteration_context(act_pos, iter_ctx);
+        iter_ctx = new_iter_ctx;
+        seen_newline = true;        // fake a newline to trigger pp_directive
+        must_emit_line_directive = true;
+
+        act_pos.set_file(iter_ctx->filename);  // initialize file position
+#if BOOST_WAVE_SUPPORT_PRAGMA_ONCE != 0
+        fs::path rfp(wave::util::create_path(iter_ctx->real_filename.c_str()));
+        std::string real_filename(rfp.string());
+        ctx.set_current_filename(real_filename.c_str());
+#endif 
+
+        ctx.set_current_relative_filename(dir_path.c_str());
+        iter_ctx->real_relative_filename = dir_path.c_str();
+
+        act_pos.set_line(iter_ctx->line);
+        act_pos.set_column(0);
+    }
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_include(): handle #include ... directives
+//
+///////////////////////////////////////////////////////////////////////////////
+
+namespace impl {
+
+    // trim all whitespace from the beginning and the end of the given string
+    template <typename StringT>
+    inline StringT 
+    trim_whitespace(StringT const &s)
+    {
+        typedef typename StringT::size_type size_type;
+
+        size_type first = s.find_first_not_of(" \t\v\f");
+        if (StringT::npos == first)
+            return StringT();
+        size_type last = s.find_last_not_of(" \t\v\f");
+        return s.substr(first, last-first+1);
+    }
+}
+
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_include(
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end, bool include_next)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// preprocess the given token sequence (the body of the #include directive)
+get_token_value<result_type, parse_node_type> get_value;
+token_sequence_type expanded;
+token_sequence_type toexpand;
+
+    std::copy(make_ref_transform_iterator(begin, get_value), 
+        make_ref_transform_iterator(end, get_value),
+        std::inserter(toexpand, toexpand.end()));
+
+    typename token_sequence_type::iterator begin2 = toexpand.begin();
+    ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, 
+        false);
+
+// now, include the file
+string_type s (impl::trim_whitespace(boost::wave::util::impl::as_string(expanded)));
+bool is_system = '<' == s[0] && '>' == s[s.size()-1];
+
+    if (!is_system && !('\"' == s[0] && '\"' == s[s.size()-1])) {
+    // should resolve into something like <...> or "..."
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, bad_include_statement, 
+            s.c_str(), act_pos);
+        return;
+    }
+    on_include(s, is_system, include_next);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_define(): handle #define directives
+//
+///////////////////////////////////////////////////////////////////////////////
+
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_define (parse_node_type const &node) 
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// retrieve the macro definition from the parse tree
+result_type macroname;
+std::vector<result_type> macroparameters;
+token_sequence_type macrodefinition;
+bool has_parameters = false;
+position_type pos(act_token.get_position());
+
+    if (!boost::wave::util::retrieve_macroname(ctx, node, 
+            BOOST_WAVE_PLAIN_DEFINE_ID, macroname, pos, false))
+        return;
+    has_parameters = boost::wave::util::retrieve_macrodefinition(node, 
+        BOOST_WAVE_MACRO_PARAMETERS_ID, macroparameters, pos, false);
+    boost::wave::util::retrieve_macrodefinition(node, 
+        BOOST_WAVE_MACRO_DEFINITION_ID, macrodefinition, pos, false);
+
+    if (has_parameters) {
+#if BOOST_WAVE_SUPPORT_VARIADICS_PLACEMARKERS != 0
+        if (boost::wave::need_variadics(ctx.get_language())) {
+        // test whether ellipsis are given, and if yes, if these are placed as the
+        // last argument, test if __VA_ARGS__ is used as a macro parameter name
+            using namespace cpplexer;
+            typedef typename std::vector<result_type>::iterator 
+                parameter_iterator_t;
+
+            bool seen_ellipses = false;
+            parameter_iterator_t end = macroparameters.end();
+            for (parameter_iterator_t pit = macroparameters.begin(); 
+                pit != end; ++pit) 
+            {
+                if (seen_ellipses) {
+                // ellipses are not the last given formal argument
+                    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                        bad_define_statement, macroname.get_value().c_str(), 
+                        (*pit).get_position());
+                    return;
+                }
+                if (T_ELLIPSIS == token_id(*pit)) 
+                    seen_ellipses = true;
+
+                // can't use __VA_ARGS__ as a argument name
+                if ("__VA_ARGS__" == (*pit).get_value()) {
+                    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                        bad_define_statement_va_args, 
+                        macroname.get_value().c_str(), (*pit).get_position());
+                    return;
+                }
+            }
+
+        // if there wasn't an ellipsis, then there shouldn't be a __VA_ARGS__ 
+        // placeholder in the definition too [C99 Standard 6.10.3.5]
+            if (!seen_ellipses) {
+                typedef typename token_sequence_type::iterator definition_iterator_t;
+
+                bool seen_va_args = false;
+                definition_iterator_t pend = macrodefinition.end();
+                for (definition_iterator_t dit = macrodefinition.begin(); 
+                     dit != pend; ++dit) 
+                {
+                    if (T_IDENTIFIER == token_id(*dit) && 
+                        "__VA_ARGS__" == (*dit).get_value())
+                    {
+                        seen_va_args = true;
+                    }
+                }
+                if (seen_va_args) {
+                // must not have seen __VA_ARGS__ placeholder
+                    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                        bad_define_statement_va_args, 
+                        macroname.get_value().c_str(), act_token.get_position());
+                    return;
+                }
+            }
+        }
+        else
+#endif // BOOST_WAVE_SUPPORT_VARIADICS_PLACEMARKERS != 0
+        {
+        // test, that there is no T_ELLIPSES given
+            using namespace cpplexer;
+            typedef typename std::vector<result_type>::iterator 
+                parameter_iterator_t;
+
+            parameter_iterator_t end = macroparameters.end();
+            for (parameter_iterator_t pit = macroparameters.begin(); 
+                pit != end; ++pit) 
+            {
+                if (T_ELLIPSIS == token_id(*pit)) {
+                // if variadics are disabled, no ellipses should be given
+                    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                        bad_define_statement, macroname.get_value().c_str(), 
+                        (*pit).get_position());
+                    return;
+                }
+            }
+        }
+    }
+
+// add the new macro to the macromap
+    ctx.add_macro_definition(macroname, has_parameters, macroparameters, 
+        macrodefinition);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_undefine(): handle #undef directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_undefine (lexer_type const &it)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// retrieve the macro name to undefine from the parse tree
+    ctx.remove_macro_definition((*it).get_value()); // throws for predefined macros
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_ifdef(): handle #ifdef directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_ifdef(
+    result_type const& found_directive, lexer_type const &it)
+//     typename parse_tree_type::const_iterator const &it)
+//     typename parse_tree_type::const_iterator const &end)
+{
+// get_token_value<result_type, parse_node_type> get_value;
+// token_sequence_type toexpand;
+// 
+//     std::copy(make_ref_transform_iterator((*begin).children.begin(), get_value), 
+//         make_ref_transform_iterator((*begin).children.end(), get_value),
+//         std::inserter(toexpand, toexpand.end()));
+
+bool is_defined = false;
+token_sequence_type directive;
+
+    directive.insert(directive.end(), *it);
+
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+    is_defined = ctx.is_defined_macro((*it).get_value()); // toexpand.begin(), toexpand.end());
+    ctx.get_hooks().evaluated_conditional_expression(directive, is_defined);
+#else
+    do {
+        is_defined = ctx.is_defined_macro((*it).get_value()); // toexpand.begin(), toexpand.end());
+    } while (ctx.get_hooks().evaluated_conditional_expression(ctx.derived(), 
+             found_directive, directive, is_defined));
+#endif
+    ctx.enter_if_block(is_defined);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_ifndef(): handle #ifndef directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_ifndef(
+    result_type const& found_directive, lexer_type const &it)
+//     typename parse_tree_type::const_iterator const &it)
+//     typename parse_tree_type::const_iterator const &end)
+{
+// get_token_value<result_type, parse_node_type> get_value;
+// token_sequence_type toexpand;
+// 
+//     std::copy(make_ref_transform_iterator((*begin).children.begin(), get_value), 
+//         make_ref_transform_iterator((*begin).children.end(), get_value),
+//         std::inserter(toexpand, toexpand.end()));
+
+bool is_defined = false;
+token_sequence_type directive;
+
+    directive.insert(directive.end(), *it);
+
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+    is_defined = ctx.is_defined_macro((*it).get_value()); // toexpand.begin(), toexpand.end());
+    ctx.get_hooks().evaluated_conditional_expression(directive, is_defined);
+#else
+    do {
+        is_defined = ctx.is_defined_macro((*it).get_value()); // toexpand.begin(), toexpand.end());
+    } while (ctx.get_hooks().evaluated_conditional_expression(ctx.derived(), 
+             found_directive, directive, is_defined));
+#endif
+    ctx.enter_if_block(!is_defined);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_else(): handle #else directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_else()
+{
+    if (!ctx.enter_else_block()) {
+    // #else without matching #if
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, missing_matching_if, 
+            "#else", act_pos);
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_endif(): handle #endif directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_endif()
+{
+    if (!ctx.exit_if_block()) {
+    // #endif without matching #if
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, missing_matching_if, 
+            "#endif", act_pos);
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  replace all remaining (== undefined) identifiers with an integer literal '0'
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::replace_undefined_identifiers(
+    token_sequence_type &expanded)
+{
+    typename token_sequence_type::iterator exp_end = expanded.end();
+    for (typename token_sequence_type::iterator exp_it = expanded.begin();
+         exp_it != exp_end; ++exp_it)
+    {
+        using namespace boost::wave;
+        
+        token_id id = token_id(*exp_it);
+        if (IS_CATEGORY(id, IdentifierTokenType) ||
+            IS_CATEGORY(id, KeywordTokenType))
+        {
+            (*exp_it).set_token_id(T_INTLIT);
+            (*exp_it).set_value("0");
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_if(): handle #if directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_if(
+    result_type const& found_directive,
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+// preprocess the given sequence into the provided list
+get_token_value<result_type, parse_node_type> get_value;
+token_sequence_type toexpand;
+
+    std::copy(make_ref_transform_iterator(begin, get_value), 
+        make_ref_transform_iterator(end, get_value),
+        std::inserter(toexpand, toexpand.end()));
+
+    impl::remove_leading_whitespace(ctx, toexpand);
+
+bool if_status = false;
+grammars::value_error status = grammars::error_noerror;
+token_sequence_type expanded;
+
+    do {
+        expanded.clear();
+
+        typename token_sequence_type::iterator begin2 = toexpand.begin();
+        ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded);
+
+    // replace all remaining (== undefined) identifiers with an integer literal '0'
+        replace_undefined_identifiers(expanded);
+
+#if BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS != 0
+        {
+            string_type outstr(boost::wave::util::impl::as_string(toexpand));
+            outstr += "(" + boost::wave::util::impl::as_string(expanded) + ")";
+            BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS_OUT << "#if " << outstr 
+                << std::endl;
+        }
+#endif
+        try {
+        // parse the expression and enter the #if block
+            if_status = grammars::expression_grammar_gen<result_type>::
+                    evaluate(expanded.begin(), expanded.end(), act_pos,
+                        ctx.get_if_block_status(), status);
+        }
+        catch (boost::wave::preprocess_exception const& e) {
+        // any errors occurred have to be dispatched to the context hooks
+            ctx.get_hooks().throw_exception(ctx.derived(), e);
+            break;
+        }
+
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+        ctx.get_hooks().evaluated_conditional_expression(toexpand, if_status);
+    } while (false);
+#else
+    } while (ctx.get_hooks().evaluated_conditional_expression(ctx.derived(), 
+                found_directive, toexpand, if_status) 
+             && status == grammars::error_noerror);
+#endif
+
+    ctx.enter_if_block(if_status);
+    if (grammars::error_noerror != status) {
+    // division or other error by zero occurred
+        string_type expression = util::impl::as_string(expanded);
+        if (0 == expression.size()) 
+            expression = "<empty expression>";
+
+        if (grammars::error_division_by_zero & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, division_by_zero, 
+                expression.c_str(), act_pos);
+        }
+        else if (grammars::error_integer_overflow & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, integer_overflow, 
+                expression.c_str(), act_pos);
+        }
+        else if (grammars::error_character_overflow & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                character_literal_out_of_range, expression.c_str(), act_pos);
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_elif(): handle #elif directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_elif(
+    result_type const& found_directive,
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+// preprocess the given sequence into the provided list
+get_token_value<result_type, parse_node_type> get_value;
+token_sequence_type toexpand;
+
+    std::copy(make_ref_transform_iterator(begin, get_value), 
+        make_ref_transform_iterator(end, get_value),
+        std::inserter(toexpand, toexpand.end()));
+
+    impl::remove_leading_whitespace(ctx, toexpand);
+
+// check current if block status
+    if (ctx.get_if_block_some_part_status()) {
+        if (!ctx.enter_elif_block(false)) {
+        // #else without matching #if
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                missing_matching_if, "#elif", act_pos);
+            // fall through...
+        }
+
+    // skip all the expression and the trailing whitespace
+    typename token_sequence_type::iterator begin2 = toexpand.begin();
+
+        impl::skip_to_eol(ctx, begin2, toexpand.end());
+        return;     // one of previous #if/#elif was true, so don't enter this #elif 
+    }
+
+// preprocess the given sequence into the provided list
+bool if_status = false;
+grammars::value_error status = grammars::error_noerror;
+token_sequence_type expanded;
+
+    do {
+        expanded.clear();
+        
+        typename token_sequence_type::iterator begin2 = toexpand.begin();
+        ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded);
+
+    // replace all remaining (== undefined) identifiers with an integer literal '0'
+        replace_undefined_identifiers(expanded);
+
+#if BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS != 0
+        {
+            string_type outstr(boost::wave::util::impl::as_string(toexpand));
+            outstr += "(" + boost::wave::util::impl::as_string(expanded) + ")";
+            BOOST_WAVE_DUMP_CONDITIONAL_EXPRESSIONS_OUT << "#elif " << outstr << std::endl;
+        }
+#endif
+
+        try {
+        // parse the expression and enter the #elif block
+            if_status = grammars::expression_grammar_gen<result_type>::
+                evaluate(expanded.begin(), expanded.end(), act_pos,
+                    ctx.get_if_block_status(), status);
+        }
+        catch (boost::wave::preprocess_exception const& e) {
+        // any errors occurred have to be dispatched to the context hooks
+            ctx.get_hooks().throw_exception(ctx.derived(), e);
+        }
+
+#if BOOST_WAVE_USE_DEPRECIATED_PREPROCESSING_HOOKS != 0
+        ctx.get_hooks().evaluated_conditional_expression(toexpand, if_status);
+    } while (false);
+#else
+    } while (ctx.get_hooks().evaluated_conditional_expression(ctx.derived(), 
+                found_directive, toexpand, if_status) 
+             && status == grammars::error_noerror);
+#endif
+
+    if (!ctx.enter_elif_block(if_status)) { 
+    // #elif without matching #if
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, missing_matching_if, 
+            "#elif", act_pos);
+        return;
+    }
+
+    if (grammars::error_noerror != status) {
+    // division or other error by zero occurred
+        string_type expression = util::impl::as_string(expanded);
+        if (0 == expression.size()) 
+            expression = "<empty expression>";
+            
+        if (grammars::error_division_by_zero & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, division_by_zero, 
+                expression.c_str(), act_pos);
+        }
+        else if (grammars::error_integer_overflow & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                integer_overflow, expression.c_str(), act_pos);
+        }
+        else if (grammars::error_character_overflow & status) {
+            BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, 
+                character_literal_out_of_range, expression.c_str(), act_pos);
+        }
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_illformed(): handles the illegal directive
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_illformed(
+    typename result_type::string_type s)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+    
+    // some messages have more than one newline at the end
+    typename string_type::size_type p = s.find_last_not_of('\n');
+    if (string_type::npos != p)
+        s = s.substr(0, p+1);
+
+    // throw the exception
+    BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, ill_formed_directive, 
+        s.c_str(), act_pos);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_line(): handle #line directives
+//
+///////////////////////////////////////////////////////////////////////////////
+
+namespace impl {
+
+    template <typename IteratorT, typename StringT>
+    bool retrieve_line_info (IteratorT first, IteratorT const &last,
+        unsigned int &line, StringT &file, 
+        boost::wave::preprocess_exception::error_code& error)
+    {
+        using namespace boost::wave;
+        token_id id = token_id(*first);
+        if (T_PP_NUMBER == id || T_INTLIT == id) {
+        // extract line number
+            using namespace std;    // some systems have atoi in namespace std
+            line = (unsigned int)atoi((*first).get_value().c_str());
+            if (0 == line)
+                error = preprocess_exception::bad_line_number;
+
+        // re-extract line number with spirit to diagnose overflow
+            using namespace boost::spirit::classic;
+            if (!parse((*first).get_value().c_str(), int_p).full)
+                error = preprocess_exception::bad_line_number;
+
+        // extract file name (if it is given)
+            while (++first != last && IS_CATEGORY(*first, WhiteSpaceTokenType)) 
+                /**/;   // skip whitespace
+
+            if (first != last) {
+                if (T_STRINGLIT != token_id(*first)) {
+                    error = preprocess_exception::bad_line_filename;
+                    return false;
+                }
+
+            StringT const &file_lit = (*first).get_value();
+
+                if ('L' == file_lit[0]) {
+                    error = preprocess_exception::bad_line_filename;
+                    return false;       // shouldn't be a wide character string 
+                }
+
+                file = file_lit.substr(1, file_lit.size()-2);
+
+            // test if there is other junk on this line
+                while (++first != last && IS_CATEGORY(*first, WhiteSpaceTokenType)) 
+                    /**/;   // skip whitespace
+            }
+            return first == last;
+        }
+        error = preprocess_exception::bad_line_statement;
+        return false;
+    }
+}
+
+template <typename ContextT> 
+inline void  
+pp_iterator_functor<ContextT>::on_line(
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// Try to extract the line number and file name from the given token list
+// directly. If that fails, preprocess the whole token sequence and try again 
+// to extract this information.
+token_sequence_type expanded;
+get_token_value<result_type, parse_node_type> get_value;
+
+    typedef typename ref_transform_iterator_generator<
+            get_token_value<result_type, parse_node_type>, 
+            typename parse_tree_type::const_iterator
+        >::type const_tree_iterator_t;
+
+const_tree_iterator_t first = make_ref_transform_iterator(begin, get_value);
+const_tree_iterator_t last = make_ref_transform_iterator(end, get_value);
+
+// try to interpret the #line body as a number followed by an optional
+// string literal
+unsigned int line = 0;
+preprocess_exception::error_code error = preprocess_exception::no_error;
+string_type file_name;
+token_sequence_type toexpand;
+
+    std::copy(first, last, std::inserter(toexpand, toexpand.end()));
+    if (!impl::retrieve_line_info(first, last, line, file_name, error)) {
+    // preprocess the body of this #line message
+        typename token_sequence_type::iterator begin2 = toexpand.begin();
+        ctx.expand_whole_tokensequence(begin2, toexpand.end(), 
+            expanded, false);
+
+        error = preprocess_exception::no_error;
+        if (!impl::retrieve_line_info(expanded.begin(), expanded.end(), 
+            line, file_name, error))
+        {
+            typename ContextT::string_type msg(
+                boost::wave::util::impl::as_string(expanded));
+            BOOST_WAVE_THROW_VAR_CTX(ctx, preprocess_exception, error, 
+                msg.c_str(), act_pos);
+            return;
+        }
+
+    // call the corresponding pp hook function
+        ctx.get_hooks().found_line_directive(ctx.derived(), expanded, line, 
+            file_name.c_str());
+    }
+    else {
+    // call the corresponding pp hook function
+        ctx.get_hooks().found_line_directive(ctx.derived(), toexpand, line, 
+            file_name.c_str());
+    }
+
+// the queues should be empty at this point
+    BOOST_ASSERT(unput_queue.empty());
+    BOOST_ASSERT(pending_queue.empty());
+
+// make sure error recovery starts on the next line
+    must_emit_line_directive = true;
+
+// diagnose possible error in detected line directive
+    if (error != preprocess_exception::no_error) {
+        typename ContextT::string_type msg(
+            boost::wave::util::impl::as_string(expanded));
+        BOOST_WAVE_THROW_VAR_CTX(ctx, preprocess_exception, error, 
+            msg.c_str(), act_pos);
+        return;
+    }
+
+// set new line number/filename only if ok
+    if (!file_name.empty()) {    // reuse current file name 
+        using boost::wave::util::impl::unescape_lit;
+        act_pos.set_file(unescape_lit(file_name).c_str());
+    }
+    act_pos.set_line(line);
+    iter_ctx->first.set_position(act_pos);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_error(): handle #error directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void 
+pp_iterator_functor<ContextT>::on_error(
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// preprocess the given sequence into the provided list
+token_sequence_type expanded;
+get_token_value<result_type, parse_node_type> get_value;
+
+typename ref_transform_iterator_generator<
+        get_token_value<result_type, parse_node_type>, 
+        typename parse_tree_type::const_iterator
+    >::type first = make_ref_transform_iterator(begin, get_value);
+
+#if BOOST_WAVE_PREPROCESS_ERROR_MESSAGE_BODY != 0
+// preprocess the body of this #error message
+token_sequence_type toexpand;
+
+    std::copy(first, make_ref_transform_iterator(end, get_value),
+        std::inserter(toexpand, toexpand.end()));
+
+    typename token_sequence_type::iterator begin2 = toexpand.begin();
+    ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, 
+        false);
+    if (!ctx.get_hooks().found_error_directive(ctx.derived(), toexpand))
+#else
+// simply copy the body of this #error message to the issued diagnostic
+// message
+    std::copy(first, make_ref_transform_iterator(end, get_value), 
+        std::inserter(expanded, expanded.end()));
+    if (!ctx.get_hooks().found_error_directive(ctx.derived(), expanded))
+#endif 
+    {
+    // report the corresponding error
+        BOOST_WAVE_STRINGTYPE msg(boost::wave::util::impl::as_string(expanded));
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, error_directive, 
+            msg.c_str(), act_pos);
+    }
+}
+
+#if BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_warning(): handle #warning directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline void 
+pp_iterator_functor<ContextT>::on_warning(
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// preprocess the given sequence into the provided list
+token_sequence_type expanded;
+get_token_value<result_type, parse_node_type> get_value;
+
+typename ref_transform_iterator_generator<
+        get_token_value<result_type, parse_node_type>, 
+        typename parse_tree_type::const_iterator
+    >::type first = make_ref_transform_iterator(begin, get_value);
+
+#if BOOST_WAVE_PREPROCESS_ERROR_MESSAGE_BODY != 0
+// preprocess the body of this #warning message
+token_sequence_type toexpand;
+
+    std::copy(first, make_ref_transform_iterator(end, get_value),
+        std::inserter(toexpand, toexpand.end()));
+
+    typename token_sequence_type::iterator begin2 = toexpand.begin();
+    ctx.expand_whole_tokensequence(begin2, toexpand.end(), expanded, 
+        false);
+    if (!ctx.get_hooks().found_warning_directive(ctx.derived(), toexpand))
+#else
+// simply copy the body of this #warning message to the issued diagnostic
+// message
+    std::copy(first, make_ref_transform_iterator(end, get_value), 
+        std::inserter(expanded, expanded.end()));
+    if (!ctx.get_hooks().found_warning_directive(ctx.derived(), expanded))
+#endif 
+    {
+    // report the corresponding error
+        BOOST_WAVE_STRINGTYPE msg(boost::wave::util::impl::as_string(expanded));
+        BOOST_WAVE_THROW_CTX(ctx, preprocess_exception, warning_directive, 
+            msg.c_str(), act_pos);
+    }
+}
+#endif // BOOST_WAVE_SUPPORT_WARNING_DIRECTIVE != 0
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  on_pragma(): handle #pragma directives
+//
+///////////////////////////////////////////////////////////////////////////////
+template <typename ContextT> 
+inline bool
+pp_iterator_functor<ContextT>::on_pragma(
+    typename parse_tree_type::const_iterator const &begin,
+    typename parse_tree_type::const_iterator const &end)
+{
+    using namespace boost::wave;
+
+    BOOST_ASSERT(ctx.get_if_block_status());
+
+// Look at the pragma token sequence and decide, if the first token is STDC
+// (see C99 standard [6.10.6.2]), if it is, the sequence must _not_ be
+// preprocessed.
+token_sequence_type expanded;
+get_token_value<result_type, parse_node_type> get_value;
+
+    typedef typename ref_transform_iterator_generator<
+            get_token_value<result_type, parse_node_type>, 
+            typename parse_tree_type::const_iterator
+        >::type const_tree_iterator_t;
+
+const_tree_iterator_t first = make_ref_transform_iterator(begin, get_value);
+const_tree_iterator_t last = make_ref_transform_iterator(end, get_value);
+
+    expanded.push_back(result_type(T_PP_PRAGMA, "#pragma", act_token.get_position()));
+    expanded.push_back(result_type(T_SPACE, " ", act_token.get_position()));
+
+    while (++first != last && IS_CATEGORY(*first, WhiteSpaceTokenType)) 
+        expanded.push_back(*first);   // skip whitespace
+
+    if (first != last) {
+        if (T_IDENTIFIER == token_id(*first) && 
+            boost::wave::need_c99(ctx.get_language()) && 
+            (*first).get_value() == "STDC") 
+        {
+        // do _not_ preprocess the token sequence
+            std::copy(first, last, std::inserter(expanded, expanded.end()));
+        }
+        else {
+#if BOOST_WAVE_PREPROCESS_PRAGMA_BODY != 0
+        // preprocess the given tokensequence
+        token_sequence_type toexpand;
+
+            std::copy(first, last, std::inserter(toexpand, toexpand.end()));
+
+            typename token_sequence_type::iterator begin2 = toexpand.begin();
+            ctx.expand_whole_tokensequence(begin2, toexpand.end(), 
+                expanded, false);
+#else
+        // do _not_ preprocess the token sequence
+            std::copy(first, last, std::inserter(expanded, expanded.end()));
+#endif
+        }
+    }
+    expanded.push_back(result_type(T_NEWLINE, "\n", act_token.get_position()));
+
+// the queues should be empty at this point
+    BOOST_ASSERT(unput_queue.empty());
+    BOOST_ASSERT(pending_queue.empty());
+
+// try to interpret the expanded #pragma body 
+    token_sequence_type pending;
+    if (interpret_pragma(expanded, pending)) {
+    // if there is some replacement text, insert it into the pending queue
+        if (!pending.empty())
+            pending_queue.splice(pending_queue.begin(), pending);
+        return true;        // this #pragma was successfully recognized
+    }
+
+#if BOOST_WAVE_EMIT_PRAGMA_DIRECTIVES != 0
+// Move the resulting token sequence into the pending_queue, so it will be 
+// returned to the caller.
+    if (boost::wave::need_emit_pragma_directives(ctx.get_language())) {
+        pending_queue.splice(pending_queue.begin(), expanded);
+        return false;       // return the whole #pragma directive
+    }
+#endif 
+    return true;            // skip the #pragma at all
+}
+
+template <typename ContextT> 
+inline bool
+pp_iterator_functor<ContextT>::interpret_pragma(
+    token_sequence_type const &pragma_body, token_sequence_type &result)
+{
+    using namespace cpplexer;
+
+    typename token_sequence_type::const_iterator end = pragma_body.end();
+    typename token_sequence_type::const_iterator it = pragma_body.begin();
+    for (++it; it != end && IS_CATEGORY(*it, WhiteSpaceTokenType); ++it) 
+        /**/;   // skip whitespace
+
+    if (it == end)      // eof reached
+        return false;
+
+    return boost::wave::util::interpret_pragma(
+        ctx.derived(), act_token, it, end, result);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+}   // namespace impl
+
+///////////////////////////////////////////////////////////////////////////////
+//  
+//  pp_iterator
+//
+//      The boost::wave::pp_iterator template is the iterator, through which
+//      the resulting preprocessed input stream is accessible.
+//  
+///////////////////////////////////////////////////////////////////////////////
+
+template <typename ContextT>
+class pp_iterator 
+:   public boost::spirit::classic::multi_pass<
+        boost::wave::impl::pp_iterator_functor<ContextT>,
+        boost::wave::util::functor_input
+    >
+{
+public:
+    typedef boost::wave::impl::pp_iterator_functor<ContextT> input_policy_type;
+
+private:
+    typedef 
+        boost::spirit::classic::multi_pass<input_policy_type, boost::wave::util::functor_input>
+        base_type;
+    typedef pp_iterator<ContextT> self_type;
+    typedef boost::wave::util::functor_input functor_input_type;
+
+public:
+    pp_iterator() 
+    {}
+
+    template <typename IteratorT>
+    pp_iterator(ContextT &ctx, IteratorT const &first, IteratorT const &last,
+        typename ContextT::position_type const &pos)
+    :   base_type(input_policy_type(ctx, first, last, pos))
+    {}
+
+    bool force_include(char const *path_, bool is_last)
+    { 
+        bool result = this->get_functor().on_include_helper(path_, path_, 
+            false, false); 
+        if (is_last) {
+            this->functor_input_type::
+                template inner<input_policy_type>::advance_input();
+        }
+        return result;
+    }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+}   // namespace wave
+}   // namespace boost
+
+// the suffix header occurs after all of the code
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_SUFFIX
+#endif
+
+#endif // !defined(CPP_ITERATOR_HPP_175CA88F_7273_43FA_9039_BCF7459E1F29_INCLUDED)