vn-verdnaturachat/ios/Pods/boost-for-react-native/boost/tti/has_data.hpp

99 lines
3.1 KiB
C++

// (C) Copyright Edward Diener 2012,2013
// Use, modification and distribution are 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).
#if !defined(BOOST_TTI_HAS_DATA_HPP)
#define BOOST_TTI_HAS_DATA_HPP
#include <boost/config.hpp>
#include <boost/preprocessor/cat.hpp>
#include <boost/type_traits/remove_const.hpp>
#include <boost/tti/gen/has_data_gen.hpp>
#include <boost/tti/detail/ddata.hpp>
/*
The succeeding comments in this file are in doxygen format.
*/
/** \file
*/
/// Expands to a metafunction which tests whether member data or static member with a particular name and type exists.
/**
trait = the name of the metafunction.
name = the name of the inner member to introspect.
generates a metafunction called "trait" where 'trait' is the macro parameter.
template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE>
struct trait
{
static const value = unspecified;
typedef mpl::bool_<true-or-false> type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'
BOOST_TTI_TP_TYPE = The type of the member data or static member.
returns = 'value' is true if the 'name' exists, with the correct data type,
otherwise 'value' is false.
*/
#define BOOST_TTI_TRAIT_HAS_DATA(trait,name) \
BOOST_TTI_DETAIL_TRAIT_HAS_DATA(trait,name) \
template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE> \
struct trait \
{ \
typedef typename \
BOOST_PP_CAT(trait,_detail_hd) \
< \
typename boost::remove_const<BOOST_TTI_TP_T>::type, \
BOOST_TTI_TP_TYPE \
>::type type; \
BOOST_STATIC_CONSTANT(bool,value=type::value); \
}; \
/**/
/// Expands to a metafunction which tests whether member data or static member data with a particular name and type exists.
/**
name = the name of the inner member.
generates a metafunction called "has_data_name" where 'name' is the macro parameter.
template<class BOOST_TTI_TP_T,class BOOST_TTI_TP_TYPE>
struct has_data_name
{
static const value = unspecified;
typedef mpl::bool_<true-or-false> type;
};
The metafunction types and return:
BOOST_TTI_TP_T = the enclosing type in which to look for our 'name'
BOOST_TTI_TP_TYPE = The type of the member data or static member.
returns = 'value' is true if the 'name' exists, with the correct data type,
otherwise 'value' is false.
*/
#define BOOST_TTI_HAS_DATA(name) \
BOOST_TTI_TRAIT_HAS_DATA \
( \
BOOST_TTI_HAS_DATA_GEN(name), \
name \
) \
/**/
#endif // BOOST_TTI_HAS_DATA_HPP