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Diffstat (limited to 'boost/geometry/algorithms/detail/check_iterator_range.hpp')
-rw-r--r-- | boost/geometry/algorithms/detail/check_iterator_range.hpp | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/boost/geometry/algorithms/detail/check_iterator_range.hpp b/boost/geometry/algorithms/detail/check_iterator_range.hpp new file mode 100644 index 0000000000..09ea7f79a0 --- /dev/null +++ b/boost/geometry/algorithms/detail/check_iterator_range.hpp @@ -0,0 +1,71 @@ +// Boost.Geometry (aka GGL, Generic Geometry Library) + +// Copyright (c) 2014, Oracle and/or its affiliates. + +// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle + +// Licensed under the Boost Software License version 1.0. +// http://www.boost.org/users/license.html + +#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_CHECK_ITERATOR_RANGE_HPP +#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_CHECK_ITERATOR_RANGE_HPP + +#include <boost/core/ignore_unused.hpp> + + +namespace boost { namespace geometry +{ + +#ifndef DOXYGEN_NO_DETAIL +namespace detail +{ + +// Check whether (each element of) an iterator range satisfies a given +// predicate. +// The predicate must be implemented as having a static apply unary +// method that returns a bool. +// By default an empty range is accepted +template <typename Predicate, bool AllowEmptyRange = true> +struct check_iterator_range +{ + template <typename InputIterator> + static inline bool apply(InputIterator first, InputIterator beyond) + { + for (InputIterator it = first; it != beyond; ++it) + { + if ( !Predicate::apply(*it) ) + { + return false; + } + } + return AllowEmptyRange || first != beyond; + } + + + // version where we can pass a predicate object + template <typename InputIterator> + static inline bool apply(InputIterator first, + InputIterator beyond, + Predicate const& predicate) + { + // in case predicate's apply method is static, MSVC will + // complain that predicate is not used + boost::ignore_unused(predicate); + + for (InputIterator it = first; it != beyond; ++it) + { + if ( !predicate.apply(*it) ) + { + return false; + } + } + return AllowEmptyRange || first != beyond; + } +}; + +} // namespace detail +#endif // DOXYGEN_NO_DETAIL + +}} // namespace boost::geometry + +#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_CHECK_ITERATOR_RANGE_HPP |