1
2 // Copyright 2015 Peter Dimov.
3 //
4 // Distributed under the Boost Software License, Version 1.0.
5 //
6 // See accompanying file LICENSE_1_0.txt or copy at
7 // http://www.boost.org/LICENSE_1_0.txt
8
9
10 #if defined(_MSC_VER)
11 #pragma warning( disable: 4244 ) // 'initializing': conversion from 'int' to 'char', possible loss of data
12 #endif
13
14 #include <boost/mp11/tuple.hpp>
15 #include <boost/mp11/detail/config.hpp>
16
17 // Technically std::tuple isn't constexpr enabled in C++11, but it works with libstdc++
18
19 #if defined( BOOST_MP11_NO_CONSTEXPR ) || ( !defined(_MSC_VER) && !defined( __GLIBCXX__ ) && __cplusplus < 201400L )
20
main()21 int main() {}
22
23 #else
24
25 #include <tuple>
26 #include <type_traits>
27
28 struct assert_is_integral
29 {
operator ()assert_is_integral30 template<class T> constexpr bool operator()( T ) const
31 {
32 static_assert( std::is_integral<T>::value, "T must be an integral type" );
33 return true;
34 }
35 };
36
main()37 int main()
38 {
39 {
40 constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
41 constexpr auto r = boost::mp11::tuple_for_each( tp, assert_is_integral() );
42 (void)r;
43 }
44
45 #if defined( __clang_major__ ) && __clang_major__ == 3 && __clang_minor__ < 9
46 // "error: default initialization of an object of const type 'const std::tuple<>' without a user-provided default constructor"
47 #else
48
49 {
50 constexpr std::tuple<> tp;
51 constexpr auto r = boost::mp11::tuple_for_each( tp, 11 );
52 static_assert( r == 11, "r == 11" );
53 }
54
55 #endif
56 }
57
58 #endif
59