Add rvalue versions of static_pointer_cast, const_pointer_cast, dynamic_pointer_cast, reinterpret_pointer_cast.

Aligns with proposed addition to std:: here: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0390r0.htm
This commit is contained in:
Chris Glover
2016-12-11 15:38:34 -05:00
parent 61075bb9df
commit 3e2ac10e94
3 changed files with 141 additions and 0 deletions

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@ -883,6 +883,50 @@ template<class T, class U> shared_ptr<T> reinterpret_pointer_cast( shared_ptr<U>
return shared_ptr<T>( r, p );
}
#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
template<class T, class U> shared_ptr<T> static_pointer_cast( shared_ptr<U> && r ) BOOST_NOEXCEPT
{
(void) static_cast< T* >( static_cast< U* >( 0 ) );
typedef typename shared_ptr<T>::element_type E;
E * p = static_cast< E* >( r.get() );
return shared_ptr<T>( std::move(r), p );
}
template<class T, class U> shared_ptr<T> const_pointer_cast( shared_ptr<U> && r ) BOOST_NOEXCEPT
{
(void) const_cast< T* >( static_cast< U* >( 0 ) );
typedef typename shared_ptr<T>::element_type E;
E * p = const_cast< E* >( r.get() );
return shared_ptr<T>( std::move(r), p );
}
template<class T, class U> shared_ptr<T> dynamic_pointer_cast( shared_ptr<U> && r ) BOOST_NOEXCEPT
{
(void) dynamic_cast< T* >( static_cast< U* >( 0 ) );
typedef typename shared_ptr<T>::element_type E;
E * p = dynamic_cast< E* >( r.get() );
return p? shared_ptr<T>( std::move(r), p ): shared_ptr<T>();
}
template<class T, class U> shared_ptr<T> reinterpret_pointer_cast( shared_ptr<U> && r ) BOOST_NOEXCEPT
{
(void) reinterpret_cast< T* >( static_cast< U* >( 0 ) );
typedef typename shared_ptr<T>::element_type E;
E * p = reinterpret_cast< E* >( r.get() );
return shared_ptr<T>( std::move(r), p );
}
#endif // !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
// get_pointer() enables boost::mem_fn to recognize shared_ptr
template<class T> inline typename shared_ptr<T>::element_type * get_pointer(shared_ptr<T> const & p) BOOST_NOEXCEPT

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@ -34,6 +34,7 @@ import testing ;
[ run auto_ptr_rv_test.cpp ]
[ run shared_ptr_alias_test.cpp ]
[ run shared_ptr_rv_test.cpp ]
[ run shared_ptr_rv_pointer_cast_test.cpp ]
[ run shared_ptr_move_test.cpp ]
[ run shared_ptr_alias_move_test.cpp ]
[ compile-fail shared_ptr_pv_fail.cpp ]

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@ -0,0 +1,96 @@
//
// shared_ptr_rv_pointer_cast_test.cpp
//
// Copyright (c) 2016 Chris Glover
//
// 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/shared_ptr.hpp>
#include <boost/detail/lightweight_test.hpp>
#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
struct X
{};
struct Y: public X
{};
struct U
{
virtual ~U() {}
};
struct V: public U
{};
struct W : public U
{};
int main()
{
{
boost::shared_ptr<X> px(new Y);
boost::shared_ptr<Y> py1 = boost::static_pointer_cast<Y>(px);
boost::shared_ptr<Y> py2 = boost::static_pointer_cast<Y>(std::move(px));
BOOST_TEST(!px);
BOOST_TEST(px.use_count() == 0);
BOOST_TEST(py1.get() == py2.get());
BOOST_TEST(!(py1 < py2 || py2 < py1));
BOOST_TEST(py1.use_count() == 2);
BOOST_TEST(py2.use_count() == 2);
}
{
boost::shared_ptr<int const volatile> px(new int);
boost::shared_ptr<int> px2 = boost::const_pointer_cast<int>(px);
boost::shared_ptr<int> px3 = boost::const_pointer_cast<int>(std::move(px));
BOOST_TEST(!px);
BOOST_TEST(px.use_count() == 0);
BOOST_TEST(px2.get() == px3.get());
BOOST_TEST(!(px2 < px3 || px2 < px3));
BOOST_TEST(px2.use_count() == 2);
BOOST_TEST(px3.use_count() == 2);
}
#if !defined( BOOST_NO_RTTI )
{
boost::shared_ptr<U> pu(new V);
boost::shared_ptr<V> pv1 = boost::dynamic_pointer_cast<V>(pu);
boost::shared_ptr<V> pv2 = boost::dynamic_pointer_cast<V>(std::move(pu));
BOOST_TEST(!pu);
BOOST_TEST(pu.use_count() == 0);
BOOST_TEST(pv1.get() == pv2.get());
BOOST_TEST(!(pv1 < pv2 || pv2 < pv1));
BOOST_TEST(pv1.use_count() == 2);
BOOST_TEST(pv2.use_count() == 2);
}
{
boost::shared_ptr<U> pu(new V);
boost::shared_ptr<W> pw = boost::dynamic_pointer_cast<W>(std::move(pu));
BOOST_TEST(!pw);
BOOST_TEST(pu);
}
#endif // !defined( BOOST_NO_RTTI )
return boost::report_errors();
}
#else // !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
int main()
{
return 0;
}
#endif // !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )