ceph/src/boost/libs/log/include/boost/log/utility/functional/begins_with.hpp

   1 /*
   2  *          Copyright Andrey Semashev 2007 - 2015.
   3  * Distributed under the Boost Software License, Version 1.0.
   4  *    (See accompanying file LICENSE_1_0.txt or copy at
   5  *          http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7 /*!
   8  * \file   begins_with.hpp
   9  * \author Andrey Semashev
  10  * \date   30.03.2008
  11  *
  12  * This header contains a predicate for checking if the provided string begins with a substring.
  13  */
  14
  15 #ifndef BOOST_LOG_UTILITY_FUNCTIONAL_BEGINS_WITH_HPP_INCLUDED_
  16 #define BOOST_LOG_UTILITY_FUNCTIONAL_BEGINS_WITH_HPP_INCLUDED_
  17
  18 #include <boost/log/detail/config.hpp>
  19 #include <boost/log/detail/header.hpp>
  20
  21 #ifdef BOOST_HAS_PRAGMA_ONCE
  22 #pragma once
  23 #endif
  24
  25 namespace boost {
  26
  27 BOOST_LOG_OPEN_NAMESPACE
  28
  29 //! The \c begins_with functor
  30 struct begins_with_fun
  31 {
  32     typedef bool result_type;
  33
  34     template< typename T, typename U >
  35     bool operator() (T const& left, U const& right) const
  36     {
  37         typedef typename T::const_iterator left_iterator;
  38         typedef typename U::const_iterator right_iterator;
  39
  40         left_iterator left_it = left.begin(), left_end = left.end();
  41         right_iterator right_it = right.begin(), right_end = right.end();
  42         for (; left_it != left_end && right_it != right_end; ++left_it, ++right_it)
  43         {
  44             if (*left_it != *right_it)
  45                 break;
  46         }
  47         return right_it == right_end;
  48     }
  49 };
  50
  51 BOOST_LOG_CLOSE_NAMESPACE // namespace log
  52
  53 } // namespace boost
  54
  55 #include <boost/log/detail/footer.hpp>
  56
  57 #endif // BOOST_LOG_UTILITY_FUNCTIONAL_BEGINS_WITH_HPP_INCLUDED_