1// Copyright Kevlin Henney, 2000-2005.
2// Copyright Alexander Nasonov, 2006-2010.
3// Copyright Antony Polukhin, 2011-2020.
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
29namespace 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

source code of include/boost/lexical_cast/detail/is_character.hpp