dnl Copyright 2002, The libsigc++ Development Team 
dnl 
dnl This library is free software; you can redistribute it and/or 
dnl modify it under the terms of the GNU Lesser General Public 
dnl License as published by the Free Software Foundation; either 
dnl version 2.1 of the License, or (at your option) any later version. 
dnl 
dnl This library is distributed in the hope that it will be useful, 
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of 
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
dnl Lesser General Public License for more details. 
dnl 
dnl You should have received a copy of the GNU Lesser General Public 
dnl License along with this library; if not, write to the Free Software 
dnl Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
dnl
divert(-1)

include(template.macros.m4)

define([DEDUCE_RESULT_TYPE],[dnl
  template <LOOP(class T_arg%1=void, CALL_SIZE)>
  struct deduce_result_type
ifelse($1,0,[dnl
    { typedef typename adaptor_type::template deduce_result_type<LOOP(_P_(T_arg%1),eval($2-1))>::type type; };
],[dnl
    { typedef typename adaptor_type::template deduce_result_type<LIST(LOOP(_P_(T_arg%1),eval($1-1)), FOR(eval($1+1),$2,[_P_(T_arg%1),]))>::type type; };
])dnl
])
define([HIDE_OPERATOR],[dnl
ifelse($2,0,,[dnl
ifelse($2,1,[dnl
  /** Invokes the wrapped functor ignoring the only argument.
   * @param _A_arg%1 Argument to be ignored.
   * @return The return value of the functor invocation.
   */
  template <class T_arg1>
  typename deduce_result_type<T_arg1>::type
  operator()(T_arg1)
    { return this->functor_(); }

  #ifndef SIGC_TEMPLATE_SPECIALIZATION_OPERATOR_OVERLOAD
  template <class T_arg1>
  typename deduce_result_type<T_arg1>::type
  sun_forte_workaround(T_arg1 _A_a1)
    { return this->functor_(); }
  #endif

],$1,0,[dnl
  /** Invokes the wrapped functor, ignoring the last argument.dnl
FOR(1, eval($2-1),[
   * @param _A_arg%1 Argument to be passed on to the functor.])
   * @param _A_arg$2 Argument to be ignored.
   * @return The return value of the functor invocation.
   */
  template <LOOP([class T_arg%1], $2)>
  typename deduce_result_type<LOOP(T_arg%1, $2)>::type
  operator()(LOOP(T_arg%1 _A_a%1, eval($2-1)), T_arg$2)
    { return this->functor_.SIGC_WORKAROUND_OPERATOR_PARENTHESES<LIST(FOR(1,eval($2-1),[_P_(T_arg%1),]))>
        (LIST(FOR(1,eval($2-1),[_A_a%1,]))); }

  #ifndef SIGC_TEMPLATE_SPECIALIZATION_OPERATOR_OVERLOAD
  template <LOOP([class T_arg%1], $2)>
  typename deduce_result_type<LOOP(T_arg%1, $2)>::type
  sun_forte_workaround(LOOP(T_arg%1 _A_a%1, eval($2-1)), T_arg$2)
    { return this->functor_.SIGC_WORKAROUND_OPERATOR_PARENTHESES<LIST(FOR(1,eval($2-1),[_P_(T_arg%1),]))>
        (LIST(FOR(1,eval($2-1),[_A_a%1,]))); }
  #endif

],[dnl
  /** Invokes the wrapped functor, ignoring the $1[]th argument.dnl
FOR(1, eval($1-1),[
   * @param _A_arg%1 Argument to be passed on to the functor.])
   * @param _A_arg$1 Argument to be ignored.dnl
FOR(eval($1+1), $2,[
   * @param _A_arg%1 Argument to be passed on to the functor.])
   * @return The return value of the functor invocation.
   */
  template <LOOP([class T_arg%1], $2)>
  typename deduce_result_type<LOOP(T_arg%1, $2)>::type
  operator()(LIST(FOR(1,eval($1-1),[T_arg%1 _A_a%1,]),T_arg$1,FOR(eval($1+1),$2,[T_arg%1 _A_a%1,])))
    { return this->functor_.SIGC_WORKAROUND_OPERATOR_PARENTHESES<LIST(FOR(1,eval($1-1),[_P_(T_arg%1),]),FOR(eval($1+1), $2,[_P_(T_arg%1),]))>
        (LIST(FOR(1,eval($1-1),[_A_a%1,]),FOR(eval($1+1),$2,[_A_a%1,]))); }

  #ifndef SIGC_TEMPLATE_SPECIALIZATION_OPERATOR_OVERLOAD
  template <LOOP([class T_arg%1], $2)>
  typename deduce_result_type<LOOP(T_arg%1, $2)>::type
  sun_forte_workaround(LIST(FOR(1,eval($1-1),[T_arg%1 _A_a%1,]),T_arg$1,FOR(eval($1+1),$2,[T_arg%1 _A_a%1,])))
    { return this->functor_.SIGC_WORKAROUND_OPERATOR_PARENTHESES<LIST(FOR(1,eval($1-1),[_P_(T_arg%1),]),FOR(eval($1+1), $2,[_P_(T_arg%1),]))>
        (LIST(FOR(1,eval($1-1),[_A_a%1,]),FOR(eval($1+1),$2,[_A_a%1,]))); }
  #endif
    
])])dnl
])
define([HIDE_FUNCTOR],[dnl
/** Adaptor that adds a dummy parameter to the wrapped functor.
 * This template specialization ignores the value of the ifelse($1,-1,[last],[$1[]th]) parameter in operator()().
 *
 * @ingroup hide
 */
template <class T_functor>
struct hide_functor <$1, T_functor> : public adapts<T_functor>
{
  typedef typename adapts<T_functor>::adaptor_type adaptor_type;

DEDUCE_RESULT_TYPE(eval($1+1),CALL_SIZE)dnl
  typedef typename adaptor_type::result_type  result_type;

FOR(eval($1+1),CALL_SIZE,[[HIDE_OPERATOR(eval($1+1),%1)]])dnl

  /** Constructs a hide_functor object that adds a dummy parameter to the passed functor.
   * @param _A_functor Functor to invoke from operator()().
   */
  explicit hide_functor(const T_functor& _A_func)
    : adapts<T_functor>(_A_func)
    {}
};

])

divert(0)dnl
__FIREWALL__
#include <sigc++/adaptors/adaptor_trait.h>

namespace sigc { 

/** @defgroup hide hide(), hide_return()
 * sigc::hide() alters an arbitrary functor in that it adds a parameter
 * whose value is ignored on invocation of the returned functor.
 * Thus you can discard one argument of a signal.
 *
 * You may optionally specify the zero-based position of the parameter
 * to ignore as a template argument. The default is to ignore the last
 * parameter.
 * (A value of @p -1 adds a parameter at the end so sigc::hide<-1>() gives the same result as sigc::hide().)
 *
 * The type of the parameter can optionally be specified if not deduced.
 *
 * @par Examples:
 * @code
 * void foo(int, int);
 * // single argument hiding ...
 * sigc::hide(&foo)(1,2,3);     // adds a dummy parameter at the back and calls foo(1,2)
 * sigc::hide<-1>(&foo)(1,2,3); // same as sigc::hide(&foo)(1,2,3) (calls foo(1,2))
 * sigc::hide<0>(&foo)(1,2,3);  // adds a dummy parameter at the beginning and calls foo(2,3)
 * sigc::hide<1>(&foo)(1,2,3);  // adds a dummy parameter in the middle and calls foo(1,3)
 * sigc::hide<2>(&foo)(1,2,3);  // adds a dummy parameter at the back and calls foo(1,2)
 * @endcode
 *
 * The functor sigc::hide() returns can be directly passed into
 * sigc::signal::connect().
 *
 * @par Example:
 * @code
 * sigc::signal<void,int> some_signal;
 * void foo();
 * some_signal.connect(sigc::hide(&foo));
 * @endcode
 *
 * sigc::hide() can be nested in order to discard multiple arguments.
 * @par Example:
 * @code
 * // multiple argument hiding ...
 * sigc::hide(sigc::hide(&foo))(1,2,3,4); // adds two dummy parameters at the back and calls foo(1,2)
 * @endcode

 * sigc::hide_return() alters an arbitrary functor by
 * dropping its return value, thus converting it to a void functor.
 *
 * For a more powerful version of this functionality see the lambda
 * library adaptor sigc::group() which can bind, hide and reorder
 * arguments arbitrarily. Although sigc::group() is more flexible,
 * sigc::hide() provides a means of hiding parameters when the total
 * number of parameters called is variable.
 *
 * @ingroup adaptors
 */

/** Adaptor that adds a dummy parameter to the wrapped functor.
 * Use the convenience function sigc::hide() to create an instance of sigc::hide_functor.
 *
 * The following template arguments are used:
 * - @e I_location Zero-based position of the dummy parameter (@p -1 for the last parameter).
 * - @e T_type Type of the dummy parameter.
 * - @e T_functor Type of the functor to wrap.
 *
 * @ingroup hide
 */
template <int I_location, class T_functor>
struct hide_functor;

FOR(-1,eval(CALL_SIZE-1),[[HIDE_FUNCTOR(%1)]])dnl

//template specialization of visit_each<>(action, functor):
/** Performs a functor on each of the targets of a functor.
 * The function overload for sigc::hide_functor performs a functor on the
 * functor stored in the sigc::hide_functor object.
 *
 * @ingroup hide
 */
template <class T_action, int I_location, class T_functor>
void visit_each(const T_action& _A_action,
                const hide_functor<I_location, T_functor>& _A_target)
{
  visit_each(_A_action, _A_target.functor_);
}


/** Creates an adaptor of type sigc::hide_functor which adds a dummy parameter to the passed functor.
 * The optional template argument @e I_location specifies the zero-based
 * position of the dummy parameter in the returned functor (@p -1 stands for the last parameter).
 *
 * @param _A_func Functor that should be wrapped.
 * @return Adaptor that executes @e _A_func, ignoring the value of the dummy parameter.
 *
 * @ingroup hide
 */
template <int I_location, class T_functor>
inline hide_functor<I_location, T_functor>
hide(const T_functor& _A_func)
  { return hide_functor<I_location, T_functor>(_A_func); }

/** Creates an adaptor of type sigc::hide_functor which adds a dummy parameter to the passed functor.
 * This overload adds a dummy parameter at the back of the functor's parameter list.
 *
 * @param _A_func Functor that should be wrapped.
 * @return Adaptor that executes @e _A_func, ignoring the value of the last parameter.
 *
 * @ingroup hide
 */
template <class T_functor>
inline hide_functor<-1, T_functor>
hide(const T_functor& _A_func)
  { return hide_functor<-1, T_functor> (_A_func); }

} /* namespace sigc */
