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// 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();
}
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