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// Copyright 2017 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
#include <boost/variant2/variant.hpp>
#include <utility>
using namespace boost::variant2;
struct X
{
int v;
X() = default;
constexpr X( int v ): v( v ) {}
constexpr operator int() const { return v; }
};
struct Y
{
int v;
constexpr Y(): v() {}
constexpr Y( int v ): v( v ) {}
constexpr operator int() const { return v; }
};
enum E
{
v
};
#define STATIC_ASSERT(...) static_assert(__VA_ARGS__, #__VA_ARGS__)
template<class T, class V> constexpr T test( V&& v )
{
V v2( std::forward<V>(v) );
return get<T>( v2 );
}
int main()
{
{
constexpr auto w = test<int>( variant<int>( 1 ) );
STATIC_ASSERT( w == 1 );
}
{
constexpr auto w = test<X>( variant<X>( 1 ) );
STATIC_ASSERT( w == 1 );
}
#if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
#else
{
constexpr auto w = test<Y>( variant<Y>( 1 ) );
STATIC_ASSERT( w == 1 );
}
#endif
{
constexpr auto w = test<int>( variant<int, float>( 1 ) );
STATIC_ASSERT( w == 1 );
}
{
constexpr auto w = test<float>( variant<int, float>( 3.0f ) );
STATIC_ASSERT( w == 3.0f );
}
{
constexpr auto w = test<float>( variant<int, int, float>( 3.0f ) );
STATIC_ASSERT( w == 3.0f );
}
{
constexpr auto w = test<X>( variant<E, E, X>( 1 ) );
STATIC_ASSERT( w == 1 );
}
{
constexpr auto w = test<X>( variant<int, int, float, float, X>( X(1) ) );
STATIC_ASSERT( w == 1 );
}
#if defined( BOOST_LIBSTDCXX_VERSION ) && BOOST_LIBSTDCXX_VERSION < 50000
#else
{
constexpr auto w = test<Y>( variant<E, E, Y>( 1 ) );
STATIC_ASSERT( w == 1 );
}
{
constexpr auto w = test<Y>( variant<int, int, float, float, Y>( Y(1) ) );
STATIC_ASSERT( w == 1 );
}
#endif
}
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