1 // Copyright Kevlin Henney, 2000-2005. 2 // Copyright Alexander Nasonov, 2006-2010. 3 // Copyright Antony Polukhin, 2011-2021. 4 // 5 // Distributed under the Boost Software License, Version 1.0. (See 6 // accompanying file LICENSE_1_0.txt or copy at 7 // http://www.boost.org/LICENSE_1_0.txt) 8 // 9 // what: lexical_cast custom keyword cast 10 // who: contributed by Kevlin Henney, 11 // enhanced with contributions from Terje Slettebo, 12 // with additional fixes and suggestions from Gennaro Prota, 13 // Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov, 14 // Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann, 15 // Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters 16 // when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014 17 18 #ifndef BOOST_LEXICAL_CAST_DETAIL_IS_CHARACTER_HPP 19 #define BOOST_LEXICAL_CAST_DETAIL_IS_CHARACTER_HPP 20 21 #include <boost/config.hpp> 22 #ifdef BOOST_HAS_PRAGMA_ONCE 23 # pragma once 24 #endif 25 26 #include <boost/type_traits/integral_constant.hpp> 27 #include <boost/type_traits/is_same.hpp> 28 29 namespace boost { 30 31 namespace detail // is_character<...> 32 { 33 // returns true, if T is one of the character types 34 template < typename T > 35 struct is_character 36 { 37 typedef BOOST_DEDUCED_TYPENAME boost::integral_constant< 38 bool, 39 boost::is_same< T, char >::value || 40 #if !defined(BOOST_NO_STRINGSTREAM) && !defined(BOOST_NO_STD_WSTRING) 41 boost::is_same< T, wchar_t >::value || 42 #endif 43 #ifndef BOOST_NO_CXX11_CHAR16_T 44 boost::is_same< T, char16_t >::value || 45 #endif 46 #ifndef BOOST_NO_CXX11_CHAR32_T 47 boost::is_same< T, char32_t >::value || 48 #endif 49 boost::is_same< T, unsigned char >::value || 50 boost::is_same< T, signed char >::value 51 > type; 52 53 BOOST_STATIC_CONSTANT(bool, value = (type::value) ); 54 }; 55 } 56 } 57 58 #endif // BOOST_LEXICAL_CAST_DETAIL_IS_CHARACTER_HPP 59 60