47 lines
1.7 KiB
Plaintext
47 lines
1.7 KiB
Plaintext
|
|
||
|
|
// Copyright (C) 2009-2012 Lorenzo Caminiti
|
||
|
|
// Distributed under the Boost Software License, Version 1.0
|
||
|
|
// (see accompanying file LICENSE_1_0.txt or a copy at
|
||
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
||
|
|
// Home at http://www.boost.org/libs/utility/identity_type
|
||
|
|
|
||
|
|
/** @file
|
||
|
|
Wrap type expressions with round parenthesis so they can be passed to macros
|
||
|
|
even if they contain commas.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef BOOST_IDENTITY_TYPE_HPP_
|
||
|
|
#define BOOST_IDENTITY_TYPE_HPP_
|
||
|
|
|
||
|
|
#include <boost/type_traits/function_traits.hpp>
|
||
|
|
|
||
|
|
/**
|
||
|
|
@brief This macro allows to wrap the specified type expression within extra
|
||
|
|
round parenthesis so the type can be passed as a single macro parameter even if
|
||
|
|
it contains commas (not already wrapped within round parenthesis).
|
||
|
|
|
||
|
|
@Params
|
||
|
|
@Param{parenthesized_type,
|
||
|
|
The type expression to be passed as macro parameter wrapped by a single set
|
||
|
|
of round parenthesis <c>(...)</c>.
|
||
|
|
This type expression can contain an arbitrary number of commas.
|
||
|
|
}
|
||
|
|
@EndParams
|
||
|
|
|
||
|
|
This macro works on any C++03 compiler (it does not use variadic macros).
|
||
|
|
|
||
|
|
This macro must be prefixed by <c>typename</c> when used within templates.
|
||
|
|
Note that the compiler will not be able to automatically determine function
|
||
|
|
template parameters when they are wrapped with this macro (these parameters
|
||
|
|
need to be explicitly specified when calling the function template).
|
||
|
|
|
||
|
|
On some compilers (like GCC), using this macro on abstract types requires to
|
||
|
|
add and remove a reference to the specified type.
|
||
|
|
*/
|
||
|
|
#define BOOST_IDENTITY_TYPE(parenthesized_type) \
|
||
|
|
/* must NOT prefix this with `::` to work with parenthesized syntax */ \
|
||
|
|
boost::function_traits< void parenthesized_type >::arg1_type
|
||
|
|
|
||
|
|
#endif // #include guard
|
||
|
|
|