ceph/src/boost/libs/mp11/test/tuple_apply_cx.cpp

   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 #include <boost/mp11/tuple.hpp>
  10 #include <boost/config.hpp>
  11
  12 // Technically std::tuple isn't constexpr enabled in C++11, but it works with libstdc++
  13
  14 #if defined( BOOST_NO_CXX11_CONSTEXPR ) || ( defined( _LIBCPP_VERSION ) && __cplusplus < 201400L )
  15
  16 int main() {}
  17
  18 #else
  19
  20 #include <tuple>
  21 #include <array>
  22 #include <utility>
  23
  24 constexpr int f( int x, int y, int z )
  25 {
  26     return x * 100 + y * 10 + z;
  27 }
  28
  29 constexpr int g( int x, int y )
  30 {
  31     return x * 10 + y;
  32 }
  33
  34 constexpr int h()
  35 {
  36     return 11;
  37 }
  38
  39 int main()
  40 {
  41     {
  42         constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
  43         constexpr auto r = boost::mp11::tuple_apply( f, tp );
  44         static_assert( r == 123, "r == 123" );
  45     }
  46
  47     {
  48         constexpr std::pair<short, char> tp{ 1, 2 };
  49         constexpr auto r = boost::mp11::tuple_apply( g, tp );
  50         static_assert( r == 12, "r == 12" );
  51     }
  52
  53     {
  54         constexpr std::array<short, 3> tp{{ 1, 2, 3 }};
  55         constexpr auto r = boost::mp11::tuple_apply( f, tp );
  56         static_assert( r == 123, "r == 123" );
  57     }
  58
  59 #if defined( __clang_major__ ) && __clang_major__ == 3 && __clang_minor__ < 9
  60 // "error: default initialization of an object of const type 'const std::tuple<>' without a user-provided default constructor"
  61 #else
  62
  63     {
  64         constexpr std::tuple<> tp;
  65         constexpr auto r = boost::mp11::tuple_apply( h, tp );
  66         static_assert( r == 11, "r == 11" );
  67     }
  68
  69 #endif
  70 }
  71
  72 #endif