mirror of
https://github.com/boostorg/conversion.git
synced 2026-02-05 06:35:16 +01:00
37 lines
1.2 KiB
C++
Executable File
37 lines
1.2 KiB
C++
Executable File
// Copyright David Abrahams 2003. Permission to copy, use,
|
|
// modify, sell and distribute this software is granted provided this
|
|
// copyright notice appears in all copies. This software is provided
|
|
// "as is" without express or implied warranty, and with no claim as
|
|
// to its suitability for any purpose.
|
|
#ifndef IMPLICIT_CAST_DWA200356_HPP
|
|
# define IMPLICIT_CAST_DWA200356_HPP
|
|
|
|
# include <boost/mpl/identity.hpp>
|
|
|
|
namespace boost {
|
|
|
|
// implementation originally suggested by C. Green in
|
|
// http://lists.boost.org/MailArchives/boost/msg00886.php
|
|
|
|
// The use of identity creates a non-deduced form, so that the
|
|
// explicit template argument must be supplied
|
|
template <typename T>
|
|
inline T implicit_cast (typename mpl::identity<T>::type x) {
|
|
return x;
|
|
}
|
|
|
|
// incomplete return type now is here
|
|
//template <typename T>
|
|
//void implicit_cast (...);
|
|
|
|
// Macro for when you need a constant expression (Gennaro Prota)
|
|
#define BOOST_IMPLICIT_CAST(dst_type, expr) \
|
|
( sizeof( implicit_cast<dst_type>(expr) ) \
|
|
, \
|
|
static_cast<dst_type>(expr) \
|
|
)
|
|
|
|
} // namespace boost
|
|
|
|
#endif // IMPLICIT_CAST_DWA200356_HPP
|