// -- select_functions.hpp -- Boost Lambda Library -------------------------- | |
// Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi) | |
// | |
// 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) | |
// | |
// For more information, see http://www.boost.org | |
#ifndef BOOST_LAMBDA_SELECT_FUNCTIONS_HPP | |
#define BOOST_LAMBDA_SELECT_FUNCTIONS_HPP | |
namespace boost { | |
namespace lambda { | |
namespace detail { | |
// select functions ------------------------------- | |
template<class Any, CALL_TEMPLATE_ARGS> | |
inline Any& select(Any& any, CALL_FORMAL_ARGS) { CALL_USE_ARGS; return any; } | |
template<class Arg, CALL_TEMPLATE_ARGS> | |
inline typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type | |
select ( const lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) { | |
return op.template call< | |
typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type | |
>(CALL_ACTUAL_ARGS); | |
} | |
template<class Arg, CALL_TEMPLATE_ARGS> | |
inline typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type | |
select ( lambda_functor<Arg>& op, CALL_FORMAL_ARGS) { | |
return op.template call< | |
typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type | |
>(CALL_ACTUAL_ARGS); | |
} | |
// ------------------------------------------------------------------------ | |
// select functions where the return type is explicitly given | |
// Note: on many functions, this return type is just discarded. | |
// The select functions are inside a class template, and the return type | |
// is a class template argument. | |
// The first implementation used function templates with an explicitly | |
// specified template parameter. | |
// However, this resulted in ambiguous calls (at least with gcc 2.95.2 | |
// and edg 2.44). Not sure whether the compilers were right or wrong. | |
template<class RET> struct r_select { | |
// Any == RET | |
template<class Any, CALL_TEMPLATE_ARGS> | |
static | |
inline RET go (Any& any, CALL_FORMAL_ARGS) { CALL_USE_ARGS; return any; } | |
template<class Arg, CALL_TEMPLATE_ARGS> | |
static | |
inline RET go (const lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) { | |
return op.template call<RET>(CALL_ACTUAL_ARGS); | |
} | |
template<class Arg, CALL_TEMPLATE_ARGS> | |
static | |
inline RET go (lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) { | |
return op.template call<RET>(CALL_ACTUAL_ARGS); | |
} | |
}; | |
} // namespace detail | |
} // namespace lambda | |
} // namespace boost | |
#endif |