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livetrax/libs/sigc++2/sigc++/visit_each.h
Paul Davis 449aab3c46 rollback to 3428, before the mysterious removal of libs/* at 3431/3432
git-svn-id: svn://localhost/ardour2/branches/3.0@3435 d708f5d6-7413-0410-9779-e7cbd77b26cf
2008-06-02 21:41:35 +00:00

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C++

// -*- c++ -*-
/*
* Copyright 2002, The libsigc++ Development Team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef _SIGC_VISIT_EACH_HPP_
#define _SIGC_VISIT_EACH_HPP_
#include <sigc++/type_traits.h>
namespace sigc {
namespace internal {
/// Helper struct for visit_each_type().
template <class T_target, class T_action>
struct limit_derived_target
{
typedef limit_derived_target<T_target, T_action> T_self;
template <bool I_derived, class T_type> struct with_type;
template <class T_type> struct with_type<false,T_type>
{ static void execute_(const T_type&, const T_self&) {} };
template <class T_type> struct with_type<true,T_type>
{ static void execute_(const T_type& _A_type, const T_self& _A_action)
{ _A_action.action_(_A_type); }
};
template <class T_type>
void operator()(const T_type& _A_type) const
{ with_type<is_base_and_derived<T_target,T_type>::value,T_type>::execute_(_A_type,*this); }
limit_derived_target(const T_action& _A_action): action_(_A_action) {}
T_action action_;
};
/// Helper struct for visit_each_type().
template <class T_target, class T_action>
struct limit_derived_target<T_target*, T_action>
{
typedef limit_derived_target<T_target*, T_action> T_self;
template <bool I_derived, class T_type> struct with_type;
template <class T_type> struct with_type<false,T_type>
{ static void execute_(const T_type&, const T_self&) {} };
template <class T_type> struct with_type<true,T_type>
{ static void execute_(const T_type& _A_type, const T_self& _A_action)
{ _A_action.action_(&_A_type); }
};
template <class T_type>
void operator()(const T_type& _A_type) const
{ with_type<is_base_and_derived<T_target,T_type>::value,T_type>::execute_(_A_type,*this); }
limit_derived_target(const T_action& _A_action): action_(_A_action) {}
T_action action_;
};
} /* namespace internal */
/** This function performs a functor on each of the targets of a functor.
* All unknown types just call @e _A_action on them.
* Add overloads that specialize the @e T_functor argument for your own
* functor types, so that subobjects get visited. This is needed to enable
* auto-disconnection support for your functor types.
*
* @par Example:
* @code
* struct some_functor
* {
* void operator()() {}
* some_possibly_sigc_trackable_derived_type some_data_member;
* some_other_functor_type some_other_functor;
* }
*
* namespace sigc
* {
* template <class T_action>
* void visit_each(const T_action& _A_action,
* const some_functor& _A_target)
* {
* visit_each(_A_action, _A_target.some_data_member);
* visit_each(_A_action, _A_target.some_other_functor);
* }
* }
* @endcode
*
* @ingroup functors
*/
template <class T_action, class T_functor>
void visit_each(const T_action& _A_action, const T_functor& _A_functor)
{ _A_action(_A_functor); }
/** This function performs a functor on each of the targets
* of a functor limited to a restricted type.
*
* @ingroup functors
*/
template <class T_type, class T_action, class T_functor>
void visit_each_type(const T_action& _A_action, const T_functor& _A_functor)
{
internal::limit_derived_target<T_type,T_action> limited_action(_A_action);
visit_each(limited_action,_A_functor);
}
} /* namespace sigc */
#endif