forked from boostorg/mp11
76 lines
1.9 KiB
C++
76 lines
1.9 KiB
C++
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// Copyright 2020 Hans Dembinski.
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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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#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 <type_traits>
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// family of test types with state
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template <int N>
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struct T {
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int value;
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constexpr T() : value{N} {};
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constexpr explicit T(int n) : value{n} {}
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};
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struct F
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{
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template<int N, int M=1> constexpr T<N+M> operator()( T<N> a, T<M> b={} ) const
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{
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return T<N+M>{a.value + b.value + 1};
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}
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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<T<1>, T<2>> tp;
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constexpr std::tuple<T<3>, T<4>> tp2;
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{
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constexpr std::tuple<T<2>, T<3>> r = boost::mp11::tuple_transform(
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F{}, tp
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);
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static_assert(std::get<0>(r).value == 3, "get<0>(r).value == 3" );
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static_assert(std::get<1>(r).value == 4, "get<1>(r).value == 4" );
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}
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{
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constexpr std::tuple<T<4>, T<6>> r = boost::mp11::tuple_transform(
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F{}, tp, tp2
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);
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static_assert(std::get<0>(r).value == 5, "get<0>(r).value == 5" );
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static_assert(std::get<1>(r).value == 7, "get<1>(r).value == 7" );
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}
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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 std::tuple<> r = boost::mp11::tuple_transform( F{}, tp );
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(void)r;
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}
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#endif
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}
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#endif
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