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
  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( __GLIBCXX__ ) && __cplusplus < 201400L )
  20
  21 int main() {}
  22
  23 #else
  24
  25 #include <tuple>
  26 #include <array>
  27 #include <utility>
  28
  29 constexpr int f( int x, int y, int z )
  30 {
  31     return x * 100 + y * 10 + z;
  32 }
  33
  34 constexpr int g( int x, int y )
  35 {
  36     return x * 10 + y;
  37 }
  38
  39 constexpr int h()
  40 {
  41     return 11;
  42 }
  43
  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