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- #ifndef BOOST_PFTO_HPP
- #define BOOST_PFTO_HPP
- // MS compatible compilers support #pragma once
- #if defined(_MSC_VER) && (_MSC_VER >= 1020)
- # pragma once
- #endif
- /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8
- // pfto.hpp: workarounds for compilers which have problems supporting
- // Partial Function Template Ordering (PFTO).
- // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com .
- // Use, modification and distribution is subject to 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)
- // See http://www.boost.org/libs/serialization for updates, documentation, and revision history.
- // PFTO version is used to specify the last argument of certain functions
- // Function it is used to support compilers that fail to support correct Partial
- // Template Ordering
- #include <boost/config.hpp>
- // some compilers can use an exta argument and use function overloading
- // to choose desired function. This extra argument is long in the default
- // function implementation and int for the rest. The function is called
- // with an int argument. This first attempts to match functions with an
- // int argument before the default one (with a long argument). This is
- // known to function with VC 6.0. On other compilers this fails (Borland)
- // or causes other problems (GCC). note: this
- #if defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
- #define BOOST_PFTO long
- #else
- #define BOOST_PFTO
- #endif
- // here's another approach. Rather than use a default function - make sure
- // there is no default at all by requiring that all function invocations
- // have a "wrapped" argument type. This solves a problem with VC 6.0
- // (and perhaps others) while implementing templated constructors.
- namespace boost {
- template<class T>
- struct pfto_wrapper {
- const T & t;
- operator const T & (){
- return t;
- }
- pfto_wrapper (const T & rhs) : t(rhs) {}
- };
- template<class T>
- pfto_wrapper<T> make_pfto_wrapper(const T & t, BOOST_PFTO int){
- return pfto_wrapper<T>(t);
- }
- template<class T>
- pfto_wrapper<T> make_pfto_wrapper(const pfto_wrapper<T> & t, int){
- return t;
- }
- } // namespace boost
- #ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
- #define BOOST_PFTO_WRAPPER(T) boost::pfto_wrapper<T>
- #define BOOST_MAKE_PFTO_WRAPPER(t) boost::make_pfto_wrapper(t, 0)
- #else
- #define BOOST_PFTO_WRAPPER(T) T
- #define BOOST_MAKE_PFTO_WRAPPER(t) t
- #endif
- #endif // BOOST_PFTO_HPP
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