1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
// Copyright 2015 Peter Dimov.
//
// Distributed under the Boost Software License, Version 1.0.
//
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
#if defined(_MSC_VER)
#pragma warning( disable: 4244 ) // 'initializing': conversion from 'int' to 'char', possible loss of data
#endif
#include <boost/mp11/tuple.hpp>
#include <boost/mp11/detail/config.hpp>
// Technically std::tuple isn't constexpr enabled in C++11, but it works with libstdc++
#if defined( BOOST_MP11_NO_CONSTEXPR ) || ( !defined(_MSC_VER) && !defined( __GLIBCXX__ ) && __cplusplus < 201400L )
int main() {}
#else
#include <tuple>
#include <type_traits>
struct assert_is_integral
{
template<class T> constexpr bool operator()( T ) const
{
static_assert( std::is_integral<T>::value, "T must be an integral type" );
return true;
}
};
int main()
{
{
constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
constexpr auto r = boost::mp11::tuple_for_each( tp, assert_is_integral() );
(void)r;
}
#if defined( __clang_major__ ) && __clang_major__ == 3 && __clang_minor__ < 9
// "error: default initialization of an object of const type 'const std::tuple<>' without a user-provided default constructor"
#else
{
constexpr std::tuple<> tp;
constexpr auto r = boost::mp11::tuple_for_each( tp, 11 );
static_assert( r == 11, "r == 11" );
}
#endif
}
#endif
|
