ceph/src/boost/libs/lambda/include/boost/lambda/detail/select_functions.hpp

   1 // -- select_functions.hpp -- Boost Lambda Library --------------------------
   2
   3 // Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi)
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8 //
   9 // For more information, see http://www.boost.org
  10
  11
  12 #ifndef BOOST_LAMBDA_SELECT_FUNCTIONS_HPP
  13 #define BOOST_LAMBDA_SELECT_FUNCTIONS_HPP
  14
  15 namespace boost {
  16 namespace lambda {
  17 namespace detail {
  18
  19
  20 // select functions -------------------------------
  21 template<class Any, CALL_TEMPLATE_ARGS>
  22 inline Any& select(Any& any, CALL_FORMAL_ARGS) { CALL_USE_ARGS; return any; }
  23
  24
  25 template<class Arg, CALL_TEMPLATE_ARGS>
  26 inline typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type
  27 select ( const lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) {
  28   return op.template call<
  29     typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type
  30   >(CALL_ACTUAL_ARGS);
  31 }
  32 template<class Arg, CALL_TEMPLATE_ARGS>
  33 inline typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type
  34 select ( lambda_functor<Arg>& op, CALL_FORMAL_ARGS) {
  35   return op.template call<
  36     typename Arg::template sig<tuple<CALL_REFERENCE_TYPES> >::type
  37   >(CALL_ACTUAL_ARGS);
  38 }
  39
  40 // ------------------------------------------------------------------------
  41 // select functions where the return type is explicitly given
  42 // Note: on many functions, this return type is just discarded.
  43 // The select functions are inside a class template, and the return type
  44 // is a class template argument.
  45 // The first implementation used function templates with an explicitly
  46 // specified template parameter.
  47 // However, this resulted in ambiguous calls (at least with gcc 2.95.2
  48 // and edg 2.44). Not sure whether the compilers were right or wrong.
  49
  50 template<class RET> struct r_select {
  51
  52 // Any == RET
  53   template<class Any, CALL_TEMPLATE_ARGS>
  54   static
  55   inline RET go (Any& any, CALL_FORMAL_ARGS) { CALL_USE_ARGS; return any; }
  56
  57
  58   template<class Arg, CALL_TEMPLATE_ARGS>
  59   static
  60   inline RET go (const lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) {
  61     return op.template call<RET>(CALL_ACTUAL_ARGS);
  62   }
  63   template<class Arg, CALL_TEMPLATE_ARGS>
  64   static
  65   inline RET go (lambda_functor<Arg>& op, CALL_FORMAL_ARGS ) {
  66     return op.template call<RET>(CALL_ACTUAL_ARGS);
  67   }
  68 };
  69
  70 } // namespace detail
  71 } // namespace lambda
  72 } // namespace boost
  73
  74 #endif