mirror of
https://github.com/yuzu-emu/ext-boost.git
synced 2024-12-23 11:55:29 +00:00
65 lines
1.5 KiB
C++
65 lines
1.5 KiB
C++
|
// Boost.Range library
|
||
|
//
|
||
|
// Copyright Neil Groves 2014. 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/libs/range/
|
||
|
//
|
||
|
#ifndef BOOST_RANGE_DETAIL_DEFAULT_CONSTRUCTIBLE_UNARY_FN_HPP_INCLUDED
|
||
|
#define BOOST_RANGE_DETAIL_DEFAULT_CONSTRUCTIBLE_UNARY_FN_HPP_INCLUDED
|
||
|
|
||
|
#include <boost/optional/optional.hpp>
|
||
|
#include <boost/mpl/if.hpp>
|
||
|
#include <boost/type_traits/has_trivial_constructor.hpp>
|
||
|
|
||
|
namespace boost
|
||
|
{
|
||
|
namespace range_detail
|
||
|
{
|
||
|
|
||
|
template<typename F, typename R>
|
||
|
class default_constructible_unary_fn_wrapper
|
||
|
{
|
||
|
public:
|
||
|
typedef R result_type;
|
||
|
|
||
|
default_constructible_unary_fn_wrapper()
|
||
|
{
|
||
|
}
|
||
|
default_constructible_unary_fn_wrapper(const F& source)
|
||
|
: m_impl(source)
|
||
|
{
|
||
|
}
|
||
|
template<typename Arg>
|
||
|
R operator()(const Arg& arg) const
|
||
|
{
|
||
|
BOOST_ASSERT(m_impl);
|
||
|
return (*m_impl)(arg);
|
||
|
}
|
||
|
template<typename Arg>
|
||
|
R operator()(Arg& arg) const
|
||
|
{
|
||
|
BOOST_ASSERT(m_impl);
|
||
|
return (*m_impl)(arg);
|
||
|
}
|
||
|
private:
|
||
|
boost::optional<F> m_impl;
|
||
|
};
|
||
|
|
||
|
template<typename F, typename R>
|
||
|
struct default_constructible_unary_fn_gen
|
||
|
{
|
||
|
typedef typename boost::mpl::if_<
|
||
|
boost::has_trivial_default_constructor<F>,
|
||
|
F,
|
||
|
default_constructible_unary_fn_wrapper<F,R>
|
||
|
>::type type;
|
||
|
};
|
||
|
|
||
|
} // namespace range_detail
|
||
|
} // namespace boost
|
||
|
|
||
|
#endif // include guard
|