[/ Copyright 2006-2007 John Maddock. 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). ] [section:regex_match regex_match] #include The algorithm [regex_match] determines whether a given regular expression matches [*all] of a given character sequence denoted by a pair of bidirectional-iterators, the algorithm is defined as follows, the main use of this function is data input validation. [important Note that the result is true only if the expression matches the *whole* of the input sequence. If you want to search for an expression somewhere within the sequence then use [regex_search]. If you want to match a prefix of the character string then use [regex_search] with the flag match_continuous set.] template bool regex_match(BidirectionalIterator first, BidirectionalIterator last, match_results& m, const basic_regex & e, match_flag_type flags = match_default); template bool regex_match(BidirectionalIterator first, BidirectionalIterator last, const basic_regex & e, match_flag_type flags = match_default); template bool regex_match(const charT* str, match_results& m, const basic_regex & e, match_flag_type flags = match_default); template bool regex_match(const basic_string& s, match_results::const_iterator, Allocator>& m, const basic_regex & e, match_flag_type flags = match_default); template bool regex_match(const charT* str, const basic_regex & e, match_flag_type flags = match_default); template bool regex_match(const basic_string& s, const basic_regex & e, match_flag_type flags = match_default); [h4 Description] template bool regex_match(BidirectionalIterator first, BidirectionalIterator last, match_results& m, const basic_regex & e, match_flag_type flags = match_default); [*Requires]: Type BidirectionalIterator meets the requirements of a Bidirectional Iterator (24.1.4). [*Effects]: Determines whether there is an exact match between the regular expression /e/, and all of the character sequence \[first, last), parameter /flags/ (see [match_flag_type]) is used to control how the expression is matched against the character sequence. Returns true if such a match exists, false otherwise. [*Throws]: `std::runtime_error` if the complexity of matching the expression against an N character string begins to exceed O(N[super 2]), or if the program runs out of stack space while matching the expression (if Boost.Regex is configured in recursive mode), or if the matcher exhausts its permitted memory allocation (if Boost.Regex is configured in non-recursive mode). [*Postconditions]: If the function returns false, then the effect on parameter /m/ is undefined, otherwise the effects on parameter /m/ are given in the table: [table [[Element][Value]] [[`m.size()`][`e.mark_count()`]] [[`m.empty()`][`false`]] [[`m.prefix().first`][`first`]] [[`m.prefix().last`][`first`]] [[`m.prefix().matched`][`false`]] [[`m.suffix().first`][`last`]] [[`m.suffix().last`][`last`]] [[`m.suffix().matched`][`false`]] [[`m[0].first`][`first`]] [[`m[0].second`][`last`]] [[`m[0].matched`][true if a full match was found, and false if it was a partial match (found as a result of the match_partial flag being set).]] [[`m[n].first`][For all integers `n < m.size()`, the start of the sequence that matched sub-expression /n/. Alternatively, if sub-expression /n/ did not participate in the match, then `last`.]] [[`m[n].second`][For all integers `n < m.size()`, the end of the sequence that matched sub-expression /n/. Alternatively, if sub-expression /n/ did not participate in the match, then `last`.]] [[`m[n].matched`][For all integers `n < m.size()`, true if sub-expression /n/ participated in the match, false otherwise.]] ] template bool regex_match(BidirectionalIterator first, BidirectionalIterator last, const basic_regex & e, match_flag_type flags = match_default); [*Effects]: Behaves "as if" by constructing an instance of `match_results what`, and then returning the result of `regex_match(first, last, what, e, flags)`. template bool regex_match(const charT* str, match_results& m, const basic_regex & e, match_flag_type flags = match_default); [*Effects]: Returns the result of `regex_match(str, str + char_traits::length(str), m, e, flags)`. template bool regex_match(const basic_string& s, match_results::const_iterator, Allocator>& m, const basic_regex & e, match_flag_type flags = match_default); [*Effects]: Returns the result of `regex_match(s.begin(), s.end(), m, e, flags)`. template bool regex_match(const charT* str, const basic_regex & e, match_flag_type flags = match_default); [*Effects]: Returns the result of `regex_match(str, str + char_traits::length(str), e, flags)`. template bool regex_match(const basic_string& s, const basic_regex & e, match_flag_type flags = match_default); [*Effects]: Returns the result of `regex_match(s.begin(), s.end(), e, flags)`. [h4 Examples] The following example processes an ftp response: #include #include #include #include using namespace boost; regex expression("([0-9]+)(\\-| |$)(.*)"); // process_ftp: // on success returns the ftp response code, and fills // msg with the ftp response message. int process_ftp(const char* response, std::string* msg) { cmatch what; if(regex_match(response, what, expression)) { // what[0] contains the whole string // what[1] contains the response code // what[2] contains the separator character // what[3] contains the text message. if(msg) msg->assign(what[3].first, what[3].second); return std::atoi(what[1].first); } // failure did not match if(msg) msg->erase(); return -1; } [endsect]