// 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 #include // Technically std::tuple isn't constexpr enabled in C++11, but it works with libstdc++ #if defined( BOOST_MP11_NO_CONSTEXPR ) || ( !defined( __GLIBCXX__ ) && __cplusplus < 201400L ) int main() {} #else #include #include #include constexpr int f( int x, int y, int z ) { return x * 100 + y * 10 + z; } constexpr int g( int x, int y ) { return x * 10 + y; } constexpr int h() { return 11; } int main() { { constexpr std::tuple tp{ 1, 2, 3 }; constexpr auto r = boost::mp11::tuple_apply( f, tp ); static_assert( r == 123, "r == 123" ); } { constexpr std::pair tp{ 1, 2 }; constexpr auto r = boost::mp11::tuple_apply( g, tp ); static_assert( r == 12, "r == 12" ); } { constexpr std::array tp{{ 1, 2, 3 }}; constexpr auto r = boost::mp11::tuple_apply( f, tp ); static_assert( r == 123, "r == 123" ); } #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_apply( h, tp ); static_assert( r == 11, "r == 11" ); } #endif } #endif