108 lines
2.3 KiB
C++
108 lines
2.3 KiB
C++
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// Copyright 2017 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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#include <boost/variant2/variant.hpp>
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#include <utility>
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using namespace boost::variant2;
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struct X
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{
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int v;
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X() = default;
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constexpr X( int v ): v( v ) {}
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constexpr operator int() const { return v; }
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};
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struct Y
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{
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int v;
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constexpr Y(): v() {}
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constexpr Y( int v ): v( v ) {}
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constexpr operator int() const { return v; }
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};
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enum E
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{
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v
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};
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#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
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template<class V, class T, class A> constexpr T test( A&& a )
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{
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V v;
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v = std::forward<A>(a);
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return get<T>(v);
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}
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int main()
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{
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{
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constexpr auto w = test<variant<int>, int>( variant<int>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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{
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constexpr auto w = test<variant<X>, X>( variant<X>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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#if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
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#else
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{
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constexpr auto w = test<variant<Y>, Y>( variant<Y>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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#endif
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{
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constexpr auto w = test<variant<int, float>, int>( variant<int, float>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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{
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constexpr auto w = test<variant<int, float>, float>( variant<int, float>( 3.0f ) );
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STATIC_ASSERT( w == 3.0f );
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}
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{
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constexpr auto w = test<variant<int, int, float>, float>( variant<int, int, float>( 3.0f ) );
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STATIC_ASSERT( w == 3.0f );
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}
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{
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constexpr auto w = test<variant<E, E, X>, X>( variant<E, E, X>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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{
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constexpr auto w = test<variant<int, int, float, float, X>, X>( variant<int, int, float, float, X>( X(1) ) );
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STATIC_ASSERT( w == 1 );
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}
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#if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
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#else
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{
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constexpr auto w = test<variant<E, E, Y>, Y>( variant<E, E, Y>( 1 ) );
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STATIC_ASSERT( w == 1 );
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}
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{
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constexpr auto w = test<variant<int, int, float, float, Y>, Y>( variant<int, int, float, float, Y>( Y(1) ) );
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STATIC_ASSERT( w == 1 );
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}
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#endif
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}
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