1
2// Copyright 2000 John Maddock (john@johnmaddock.co.uk)
3// Copyright 2002 Aleksey Gurtovoy (agurtovoy@meta-comm.com)
4//
5// Use, modification and distribution are subject to the Boost Software License,
6// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt).
8//
9// See http://www.boost.org/libs/type_traits for most recent version including documentation.
10
11#ifndef BOOST_TT_IS_FUNCTION_HPP_INCLUDED
12#define BOOST_TT_IS_FUNCTION_HPP_INCLUDED
13
14#include <boost/type_traits/is_reference.hpp>
15#include <boost/type_traits/detail/config.hpp>
16
17#if !defined(BOOST_TT_TEST_MS_FUNC_SIGS)
18# include <boost/type_traits/detail/is_function_ptr_helper.hpp>
19#else
20# include <boost/type_traits/detail/is_function_ptr_tester.hpp>
21# include <boost/type_traits/detail/yes_no_type.hpp>
22#endif
23
24// is a type a function?
25// Please note that this implementation is unnecessarily complex:
26// we could just use !is_convertible<T*, const volatile void*>::value,
27// except that some compilers erroneously allow conversions from
28// function pointers to void*.
29
30namespace boost {
31
32#if !defined( __CODEGEARC__ )
33
34namespace detail {
35
36#if !defined(BOOST_TT_TEST_MS_FUNC_SIGS)
37template<bool is_ref = true>
38struct is_function_chooser
39{
40 template< typename T > struct result_
41 : public false_type {};
42};
43
44template <>
45struct is_function_chooser<false>
46{
47 template< typename T > struct result_
48 : public ::boost::type_traits::is_function_ptr_helper<T*> {};
49};
50
51template <typename T>
52struct is_function_impl
53 : public is_function_chooser< ::boost::is_reference<T>::value >
54 ::BOOST_NESTED_TEMPLATE result_<T>
55{
56};
57
58#else
59
60template <typename T>
61struct is_function_impl
62{
63#if BOOST_WORKAROUND(BOOST_MSVC_FULL_VER, >= 140050000)
64#pragma warning(push)
65#pragma warning(disable:6334)
66#endif
67 static T* t;
68 BOOST_STATIC_CONSTANT(
69 bool, value = sizeof(::boost::type_traits::is_function_ptr_tester(t))
70 == sizeof(::boost::type_traits::yes_type)
71 );
72#if BOOST_WORKAROUND(BOOST_MSVC_FULL_VER, >= 140050000)
73#pragma warning(pop)
74#endif
75};
76
77template <typename T>
78struct is_function_impl<T&> : public false_type
79{};
80#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
81template <typename T>
82struct is_function_impl<T&&> : public false_type
83{};
84#endif
85
86#endif
87
88} // namespace detail
89
90#endif // !defined( __CODEGEARC__ )
91
92#if defined( __CODEGEARC__ )
93template <class T> struct is_function : integral_constant<bool, __is_function(T)> {};
94#else
95template <class T> struct is_function : integral_constant<bool, ::boost::detail::is_function_impl<T>::value> {};
96#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
97template <class T> struct is_function<T&&> : public false_type {};
98#endif
99#endif
100} // namespace boost
101
102#endif // BOOST_TT_IS_FUNCTION_HPP_INCLUDED
103

source code of boost/boost/type_traits/is_function.hpp