319 lines
11 KiB
Plaintext
319 lines
11 KiB
Plaintext
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// (C) Copyright Ion Gaztanaga 2012-2012.
|
|
// 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)
|
|
//
|
|
// See http://www.boost.org/libs/move for documentation.
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
//! \file
|
|
//! This header defines core utilities to ease the development
|
|
//! of move-aware functions. This header minimizes dependencies
|
|
//! from other libraries.
|
|
|
|
#ifndef BOOST_MOVE_MOVE_UTILITY_CORE_HPP
|
|
#define BOOST_MOVE_MOVE_UTILITY_CORE_HPP
|
|
|
|
#ifndef BOOST_CONFIG_HPP
|
|
# include <boost/config.hpp>
|
|
#endif
|
|
#
|
|
#if defined(BOOST_HAS_PRAGMA_ONCE)
|
|
# pragma once
|
|
#endif
|
|
|
|
#include <boost/move/detail/config_begin.hpp>
|
|
#include <boost/move/detail/workaround.hpp> //forceinline
|
|
#include <boost/move/core.hpp>
|
|
#include <boost/move/detail/meta_utils.hpp>
|
|
#include <boost/static_assert.hpp>
|
|
|
|
#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
|
|
namespace boost {
|
|
|
|
template<class T>
|
|
struct enable_move_utility_emulation
|
|
{
|
|
static const bool value = true;
|
|
};
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// move()
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< T &
|
|
, enable_move_utility_emulation<T>
|
|
, has_move_emulation_disabled<T>
|
|
>::type
|
|
move(T& x) BOOST_NOEXCEPT
|
|
{
|
|
return x;
|
|
}
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< rv<T>&
|
|
, enable_move_utility_emulation<T>
|
|
, has_move_emulation_enabled<T>
|
|
>::type
|
|
move(T& x) BOOST_NOEXCEPT
|
|
{
|
|
return *BOOST_MOVE_TO_RV_CAST(::boost::rv<T>*, ::boost::move_detail::addressof(x) );
|
|
}
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< rv<T>&
|
|
, enable_move_utility_emulation<T>
|
|
, has_move_emulation_enabled<T>
|
|
>::type
|
|
move(rv<T>& x) BOOST_NOEXCEPT
|
|
{
|
|
return x;
|
|
}
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// forward()
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< T &
|
|
, enable_move_utility_emulation<T>
|
|
, ::boost::move_detail::is_rv<T>
|
|
>::type
|
|
forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
|
|
{
|
|
return const_cast<T&>(x);
|
|
}
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< const T &
|
|
, enable_move_utility_emulation<T>
|
|
, ::boost::move_detail::is_not_rv<T>
|
|
>::type
|
|
forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
|
|
{
|
|
return x;
|
|
}
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// move_if_not_lvalue_reference()
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< T &
|
|
, enable_move_utility_emulation<T>
|
|
, ::boost::move_detail::is_rv<T>
|
|
>::type
|
|
move_if_not_lvalue_reference(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT
|
|
{
|
|
return const_cast<T&>(x);
|
|
}
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< typename ::boost::move_detail::add_lvalue_reference<T>::type
|
|
, enable_move_utility_emulation<T>
|
|
, ::boost::move_detail::is_not_rv<T>
|
|
, ::boost::move_detail::or_
|
|
< ::boost::move_detail::is_lvalue_reference<T>
|
|
, has_move_emulation_disabled<T>
|
|
>
|
|
>::type
|
|
move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type &x) BOOST_NOEXCEPT
|
|
{
|
|
return x;
|
|
}
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::enable_if_and
|
|
< rv<T>&
|
|
, enable_move_utility_emulation<T>
|
|
, ::boost::move_detail::is_not_rv<T>
|
|
, ::boost::move_detail::and_
|
|
< ::boost::move_detail::not_< ::boost::move_detail::is_lvalue_reference<T> >
|
|
, has_move_emulation_enabled<T>
|
|
>
|
|
>::type
|
|
move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type &x) BOOST_NOEXCEPT
|
|
{
|
|
return move(x);
|
|
}
|
|
|
|
} //namespace boost
|
|
|
|
#else //#if defined(BOOST_NO_CXX11_RVALUE_REFERENCES) && !defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
|
|
#if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
|
|
#include <utility>
|
|
|
|
namespace boost{
|
|
|
|
using ::std::move;
|
|
using ::std::forward;
|
|
|
|
} //namespace boost
|
|
|
|
#else //!BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE
|
|
|
|
namespace boost {
|
|
|
|
//! This trait's internal boolean `value` is false in compilers with rvalue references
|
|
//! and true in compilers without rvalue references.
|
|
//!
|
|
//! A user can specialize this trait for a type T to false to SFINAE out `move` and `forward`
|
|
//! so that the user can define a different move emulation for that type in namespace boost
|
|
//! (e.g. another Boost library for its types) and avoid any overload ambiguity.
|
|
template<class T>
|
|
struct enable_move_utility_emulation
|
|
{
|
|
static const bool value = false;
|
|
};
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// move
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
#if defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
//! This function provides a way to convert a reference into a rvalue reference
|
|
//! in compilers with rvalue references. For other compilers if `T` is Boost.Move
|
|
//! enabled type then it converts `T&` into <tt>::boost::rv<T> &</tt> so that
|
|
//! move emulation is activated, else it returns `T &`.
|
|
template <class T>
|
|
rvalue_reference move(input_reference) noexcept;
|
|
|
|
#elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
|
|
|
|
//Old move approach, lvalues could bind to rvalue references
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::remove_reference<T>::type && move(T&& t) BOOST_NOEXCEPT
|
|
{ return t; }
|
|
|
|
#else //BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE typename ::boost::move_detail::remove_reference<T>::type && move(T&& t) BOOST_NOEXCEPT
|
|
{ return static_cast<typename ::boost::move_detail::remove_reference<T>::type &&>(t); }
|
|
|
|
#endif //BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// forward
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
#if defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
//! This function provides limited form of forwarding that is usually enough for
|
|
//! in-place construction and avoids the exponential overloading for
|
|
//! achieve the limited forwarding in C++03.
|
|
//!
|
|
//! For compilers with rvalue references this function provides perfect forwarding.
|
|
//!
|
|
//! Otherwise:
|
|
//! * If input_reference binds to const ::boost::rv<T> & then it output_reference is
|
|
//! ::boost::rv<T> &
|
|
//!
|
|
//! * Else, output_reference is equal to input_reference.
|
|
template <class T> output_reference forward(input_reference) noexcept;
|
|
#elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
|
|
|
|
//Old move approach, lvalues could bind to rvalue references
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& forward(typename ::boost::move_detail::identity<T>::type&& t) BOOST_NOEXCEPT
|
|
{ return t; }
|
|
|
|
#else //Old move
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& forward(typename ::boost::move_detail::remove_reference<T>::type& t) BOOST_NOEXCEPT
|
|
{ return static_cast<T&&>(t); }
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& forward(typename ::boost::move_detail::remove_reference<T>::type&& t) BOOST_NOEXCEPT
|
|
{
|
|
//"boost::forward<T> error: 'T' is a lvalue reference, can't forward as rvalue.";
|
|
BOOST_STATIC_ASSERT(!boost::move_detail::is_lvalue_reference<T>::value);
|
|
return static_cast<T&&>(t);
|
|
}
|
|
|
|
#endif //BOOST_MOVE_DOXYGEN_INVOKED
|
|
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// move_if_not_lvalue_reference
|
|
//
|
|
//////////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
#if defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
//! <b>Effects</b>: Calls `boost::move` if `input_reference` is not a lvalue reference.
|
|
//! Otherwise returns the reference
|
|
template <class T> output_reference move_if_not_lvalue_reference(input_reference) noexcept;
|
|
#elif defined(BOOST_MOVE_OLD_RVALUE_REF_BINDING_RULES)
|
|
|
|
//Old move approach, lvalues could bind to rvalue references
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& move_if_not_lvalue_reference(typename ::boost::move_detail::identity<T>::type&& t) BOOST_NOEXCEPT
|
|
{ return t; }
|
|
|
|
#else //Old move
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type& t) BOOST_NOEXCEPT
|
|
{ return static_cast<T&&>(t); }
|
|
|
|
template <class T>
|
|
BOOST_MOVE_FORCEINLINE T&& move_if_not_lvalue_reference(typename ::boost::move_detail::remove_reference<T>::type&& t) BOOST_NOEXCEPT
|
|
{
|
|
//"boost::forward<T> error: 'T' is a lvalue reference, can't forward as rvalue.";
|
|
BOOST_STATIC_ASSERT(!boost::move_detail::is_lvalue_reference<T>::value);
|
|
return static_cast<T&&>(t);
|
|
}
|
|
|
|
#endif //BOOST_MOVE_DOXYGEN_INVOKED
|
|
|
|
} //namespace boost {
|
|
|
|
#endif //#if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE)
|
|
|
|
#endif //BOOST_NO_CXX11_RVALUE_REFERENCES
|
|
|
|
#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
|
|
namespace boost{
|
|
namespace move_detail{
|
|
|
|
template <typename T>
|
|
typename boost::move_detail::add_rvalue_reference<T>::type declval();
|
|
|
|
} //namespace move_detail{
|
|
} //namespace boost{
|
|
|
|
#endif //#if !defined(BOOST_MOVE_DOXYGEN_INVOKED)
|
|
|
|
|
|
#include <boost/move/detail/config_end.hpp>
|
|
|
|
#endif //#ifndef BOOST_MOVE_MOVE_UTILITY_CORE_HPP
|