1// Copyright David Abrahams 2006.
2// Distributed under the Boost Software License, Version 1.0.
3// (See accompanying file LICENSE_1_0.txt or copy at
4// http://www.boost.org/LICENSE_1_0.txt)
5
6#ifndef BOOST_PARAMETER_AUX_PREPROCESSOR_IMPL_PARENTHESIZED_TYPE_HPP
7#define BOOST_PARAMETER_AUX_PREPROCESSOR_IMPL_PARENTHESIZED_TYPE_HPP
8
9namespace boost { namespace parameter { namespace aux {
10
11 // A metafunction that transforms void(*)(T) -> T
12 template <typename UnaryFunctionPointer>
13 struct unaryfunptr_arg_type;
14
15 template <typename Arg>
16 struct unaryfunptr_arg_type<void(*)(Arg)>
17 {
18 typedef Arg type;
19 };
20
21 template <>
22 struct unaryfunptr_arg_type<void(*)(void)>
23 {
24 typedef void type;
25 };
26}}} // namespace boost::parameter::aux
27
28// A macro that takes a parenthesized C++ type name (T) and transforms it
29// into an un-parenthesized type expression equivalent to T.
30#define BOOST_PARAMETER_PARENTHESIZED_TYPE(x) \
31 ::boost::parameter::aux::unaryfunptr_arg_type< void(*)x >::type
32
33#endif // include guard
34
35

source code of boost/libs/parameter/include/boost/parameter/aux_/preprocessor/impl/parenthesized_type.hpp