vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/signals2/detail/signals_common.hpp

78 lines
2.4 KiB
C++

// Boost.Signals library
// Copyright Douglas Gregor 2001-2004.
// Copyright Frank Mori Hess 2007. Use, modification and
// distribution is subject to 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)
// For more information, see http://www.boost.org
#ifndef BOOST_SIGNALS2_SIGNALS_COMMON_HPP
#define BOOST_SIGNALS2_SIGNALS_COMMON_HPP
#include <boost/mpl/bool.hpp>
#include <boost/mpl/if.hpp>
#include <boost/ref.hpp>
#include <boost/signals2/signal_base.hpp>
#include <boost/type_traits/is_base_of.hpp>
namespace boost {
namespace signals2 {
namespace detail {
// Determine if the given type T is a signal
template<typename T>
class is_signal: public mpl::bool_<is_base_of<signal_base, T>::value>
{};
// A slot can be a signal, a reference to a function object, or a
// function object.
struct signal_tag {};
struct reference_tag {};
struct value_tag {};
// Classify the given slot as a signal, a reference-to-slot, or a
// standard slot
template<typename S>
class get_slot_tag {
typedef typename mpl::if_<is_signal<S>,
signal_tag, value_tag>::type signal_or_value;
public:
typedef typename mpl::if_<is_reference_wrapper<S>,
reference_tag,
signal_or_value>::type type;
};
// Get the slot so that it can be copied
template<typename F>
typename F::weak_signal_type
get_invocable_slot(const F &signal, signal_tag)
{ return typename F::weak_signal_type(signal); }
template<typename F>
const F&
get_invocable_slot(const F& f, reference_tag)
{ return f; }
template<typename F>
const F&
get_invocable_slot(const F& f, value_tag)
{ return f; }
// Determines the type of the slot - is it a signal, a reference to a
// slot or just a normal slot.
template<typename F>
typename get_slot_tag<F>::type
tag_type(const F&)
{
typedef typename get_slot_tag<F>::type
the_tag_type;
the_tag_type tag = the_tag_type();
return tag;
}
} // end namespace detail
} // end namespace signals2
} // end namespace boost
#endif // BOOST_SIGNALS2_SIGNALS_COMMON_HPP