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 <array>
27 #include <utility>
28
f(int x,int y,int z)29 constexpr int f( int x, int y, int z )
30 {
31 return x * 100 + y * 10 + z;
32 }
33
g(int x,int y)34 constexpr int g( int x, int y )
35 {
36 return x * 10 + y;
37 }
38
h()39 constexpr int h()
40 {
41 return 11;
42 }
43
main()44 int main()
45 {
46 {
47 constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
48 constexpr auto r = boost::mp11::tuple_apply( f, tp );
49 static_assert( r == 123, "r == 123" );
50 }
51
52 {
53 constexpr std::pair<short, char> tp{ 1, 2 };
54 constexpr auto r = boost::mp11::tuple_apply( g, tp );
55 static_assert( r == 12, "r == 12" );
56 }
57
58 {
59 constexpr std::array<short, 3> tp{{ 1, 2, 3 }};
60 constexpr auto r = boost::mp11::tuple_apply( f, tp );
61 static_assert( r == 123, "r == 123" );
62 }
63
64 #if defined( __clang_major__ ) && __clang_major__ == 3 && __clang_minor__ < 9
65 // "error: default initialization of an object of const type 'const std::tuple<>' without a user-provided default constructor"
66 #else
67
68 {
69 constexpr std::tuple<> tp;
70 constexpr auto r = boost::mp11::tuple_apply( h, tp );
71 static_assert( r == 11, "r == 11" );
72 }
73
74 #endif
75 }
76
77 #endif
78