78 lines
1.7 KiB
C++
78 lines
1.7 KiB
C++
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// Copyright 2015 Peter Dimov.
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//
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// Distributed under the Boost Software License, Version 1.0.
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//
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// See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt
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#if defined(_MSC_VER)
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#pragma warning( disable: 4244 ) // 'initializing': conversion from 'int' to 'char', possible loss of data
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#endif
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#include <boost/mp11/tuple.hpp>
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#include <boost/mp11/detail/config.hpp>
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// Technically std::tuple isn't constexpr enabled in C++11, but it works with libstdc++
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#if defined( BOOST_MP11_NO_CONSTEXPR ) || ( !defined( __GLIBCXX__ ) && __cplusplus < 201400L )
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int main() {}
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#else
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#include <tuple>
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#include <array>
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#include <utility>
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constexpr int f( int x, int y, int z )
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{
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return x * 100 + y * 10 + z;
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}
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constexpr int g( int x, int y )
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{
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return x * 10 + y;
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}
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constexpr int h()
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{
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return 11;
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}
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int main()
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{
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{
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constexpr std::tuple<int, short, char> tp{ 1, 2, 3 };
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constexpr auto r = boost::mp11::tuple_apply( f, tp );
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static_assert( r == 123, "r == 123" );
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}
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{
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constexpr std::pair<short, char> tp{ 1, 2 };
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constexpr auto r = boost::mp11::tuple_apply( g, tp );
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static_assert( r == 12, "r == 12" );
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}
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{
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constexpr std::array<short, 3> tp{{ 1, 2, 3 }};
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constexpr auto r = boost::mp11::tuple_apply( f, tp );
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static_assert( r == 123, "r == 123" );
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}
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#if defined( __clang_major__ ) && __clang_major__ == 3 && __clang_minor__ < 9
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// "error: default initialization of an object of const type 'const std::tuple<>' without a user-provided default constructor"
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#else
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{
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constexpr std::tuple<> tp;
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constexpr auto r = boost::mp11::tuple_apply( h, tp );
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static_assert( r == 11, "r == 11" );
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}
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#endif
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}
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#endif
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