109 lines
2.7 KiB
C++
109 lines
2.7 KiB
C++
// Copyright Daniel Wallin 2006.
|
|
// 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/parameter/config.hpp>
|
|
|
|
#if (BOOST_PARAMETER_MAX_ARITY < 2)
|
|
#error Define BOOST_PARAMETER_MAX_ARITY as 2 or greater.
|
|
#endif
|
|
#if !defined(BOOST_PARAMETER_HAS_PERFECT_FORWARDING) && \
|
|
(BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY < 2)
|
|
#error Define BOOST_PARAMETER_EXPONENTIAL_OVERLOAD_THRESHOLD_ARITY \
|
|
as 2 or greater.
|
|
#endif
|
|
|
|
#include <boost/parameter/preprocessor.hpp>
|
|
#include <boost/parameter/name.hpp>
|
|
#include <boost/parameter/aux_/preprocessor/nullptr.hpp>
|
|
#include <boost/tuple/tuple.hpp>
|
|
#include <boost/core/enable_if.hpp>
|
|
#include <string>
|
|
|
|
#if defined(BOOST_PARAMETER_CAN_USE_MP11)
|
|
#include <boost/mp11/utility.hpp>
|
|
#include <type_traits>
|
|
#else
|
|
#include <boost/mpl/bool.hpp>
|
|
#include <boost/mpl/if.hpp>
|
|
#include <boost/type_traits/is_convertible.hpp>
|
|
#endif
|
|
|
|
namespace test {
|
|
|
|
BOOST_PARAMETER_NAME(x)
|
|
|
|
#if defined(BOOST_PARAMETER_CAN_USE_MP11)
|
|
template <typename T, typename Args>
|
|
using predicate = std::is_convertible<T,char const*>;
|
|
|
|
BOOST_PARAMETER_FUNCTION((int), sfinae, test::tag,
|
|
(deduced
|
|
(optional
|
|
(x
|
|
, *(boost::mp11::mp_quote<test::predicate>)
|
|
, static_cast<char const*>(BOOST_PARAMETER_AUX_PP_NULLPTR)
|
|
)
|
|
)
|
|
)
|
|
)
|
|
#else // !defined(BOOST_PARAMETER_CAN_USE_MP11)
|
|
struct predicate
|
|
{
|
|
template <typename T, typename Args>
|
|
struct apply
|
|
: boost::mpl::if_<
|
|
boost::is_convertible<T,char const*>
|
|
, boost::mpl::true_
|
|
, boost::mpl::false_
|
|
>
|
|
{
|
|
};
|
|
};
|
|
|
|
BOOST_PARAMETER_FUNCTION((int), sfinae, test::tag,
|
|
(deduced
|
|
(optional
|
|
(x
|
|
, *(test::predicate)
|
|
, static_cast<char const*>(BOOST_PARAMETER_AUX_PP_NULLPTR)
|
|
)
|
|
)
|
|
)
|
|
)
|
|
#endif // BOOST_PARAMETER_CAN_USE_MP11
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
template <typename A0>
|
|
typename boost::enable_if<
|
|
#if defined(BOOST_PARAMETER_CAN_USE_MP11)
|
|
std::is_same<int,A0>
|
|
#else
|
|
typename boost::mpl::if_<
|
|
boost::is_same<int,A0>
|
|
, boost::mpl::true_
|
|
, boost::mpl::false_
|
|
>::type
|
|
#endif
|
|
, int
|
|
>::type
|
|
sfinae(A0 const& a0)
|
|
{
|
|
return 0;
|
|
}
|
|
} // namespace test
|
|
|
|
#include <boost/core/lightweight_test.hpp>
|
|
|
|
int main()
|
|
{
|
|
BOOST_TEST_EQ(1, test::sfinae());
|
|
BOOST_TEST_EQ(1, test::sfinae("foo"));
|
|
BOOST_TEST_EQ(0, test::sfinae(1));
|
|
return boost::report_errors();
|
|
}
|
|
|