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rherilierkjellahl
rherilier
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kjellahl
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signal_connect: Add helper functions to ease connecting functions or methods to signals
Those helper functions have 2 main usages: * avoid writing template parameters in case of method or function overloading; * wrap use of sigc::mem_fun or sigc::ptr_fun when possible. unsupported cases: * lambda functions; * std::function (or alike); * volatile functions; * const? volatile methods; * binding with sigc::bind.
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‎sigc++/filelist.am

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@@ -27,6 +27,7 @@ sigc_public_h = \
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scoped_connection.h \
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signal.h \
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signal_base.h \
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signal_connect.h \
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slot.h \
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trackable.h \
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tuple-utils/tuple_cdr.h \

‎sigc++/meson.build

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@@ -25,6 +25,7 @@ sigc_h_files = [
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'scoped_connection.h',
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'signal.h',
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'signal_base.h',
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'signal_connect.h',
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'slot.h',
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'trackable.h',
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'type_traits.h',

‎sigc++/sigc++.h

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#include <sigc++/connection.h>
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#include <sigc++/scoped_connection.h>
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#include <sigc++/trackable.h>
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#include <sigc++/signal_connect.h>
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#include <sigc++/adaptors/adaptors.h>
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#include <sigc++/functors/functors.h>
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‎sigc++/signal_base.h

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@@ -281,6 +281,22 @@ struct SIGC_API signal_impl_holder
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* a @ref sigc::slot<T_return(T_arg...)> "sigc::slot"
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* and connected to a signal. See @ref slot "Slots" and
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* @ref sigc::signal_with_accumulator::connect() "sigc::signal::connect()".
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*
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* Use @ref sigc::signal_connect() to connect a method or function to a signal
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* without having to explicitly write the required template parameters in case
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* of method or function overloading.
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*
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* @code
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* sigc::signal<void(int)> sig;
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* void fun(int);
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* void fun(double);
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* sig.connect(sigc::ptr_fun<void, int>(fun));
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* // or more simply:
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* sigc::signal_connect(sig, fun);
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* @endcode
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*
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* It can also be used as a replacement for calling signal::connect() with a
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* sigc::mem_fun() or a sigc::ptr_fun().
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*/
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// TODO: When we can break ABI, let signal_base derive from trackable again,

‎sigc++/signal_connect.h

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/*
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* Copyright 2024, The libsigc++ Development Team
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#ifndef SIGC_SIGNAL_CONNECT_H
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#define SIGC_SIGNAL_CONNECT_H
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#include <sigc++/signal.h>
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#include <sigc++/functors/ptr_fun.h>
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#include <sigc++/functors/mem_fun.h>
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namespace sigc
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{
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/** Connect a function to a signal
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* @param signal The signal to connect to.
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* @param fun The function that should be wrapped.
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* @return A connection.
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*
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* @ingroup signal
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*/
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template<typename T_return, typename... T_arg>
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inline connection
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signal_connect(signal<T_return(T_arg...)>& signal, T_return (*fun)(T_arg...))
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{
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return signal.connect(ptr_fun<T_return, T_arg...>(fun));
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}
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/** Connect a non-const method to a signal
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* @param signal The signal to connect to.
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* @param obj Reference to object instance the functor should operate on.
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* @param fun Pointer to method that should be wrapped.
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* @return A connection.
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*
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* @ingroup signal
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*/
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template<typename T_return, typename T_obj, typename... T_arg>
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inline connection
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signal_connect(signal<T_return(T_arg...)>& signal, /**/ T_obj& obj, T_return (T_obj::*fun)(T_arg...))
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{
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return signal.connect(mem_fun<T_return, T_obj, T_obj, T_arg...>(obj, fun));
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}
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/** Connect a const method to a signal
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* @param signal The signal to connect to.
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* @param obj Reference to object instance the functor should operate on.
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* @param fun Pointer to method that should be wrapped.
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* @return A connection.
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*
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* @ingroup signal
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*/
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#if SIGC_MSC
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/* MSVC needs to distinguish object's class and method's class (using the
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* template parameter T_obj2) to avoid raising error C2672 (no matching
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* overloaded function found) when signal_connect(...) is called with a
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* const object.
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*/
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template<typename T_return, typename T_obj, typename T_obj2, typename... T_arg>
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inline connection
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signal_connect(signal<T_return(T_arg...)>& signal, /*const*/ T_obj& obj, T_return (T_obj2::*fun)(T_arg...) const)
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{
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return signal.connect(mem_fun<T_return, T_obj, T_obj, T_arg...>(obj, fun));
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}
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#else
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template<typename T_return, typename T_obj, typename... T_arg>
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inline connection
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signal_connect(signal<T_return(T_arg...)>& signal, /*const*/ T_obj& obj, T_return (T_obj::*fun)(T_arg...) const)
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{
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return signal.connect(mem_fun<T_return, T_obj, T_obj, T_arg...>(obj, fun));
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}
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#endif
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} /* namespace sigc */
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#endif /* SIGC_SIGNAL_CONNECT_H */
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‎tests/CMakeLists.txt

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@@ -42,6 +42,7 @@ set (TEST_SOURCE_FILES
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test_rvalue_ref.cc
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test_scoped_connection.cc
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test_signal.cc
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test_signal_connect.cc
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test_signal_move.cc
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test_size.cc
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test_slot.cc

‎tests/Makefile.am

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@@ -49,6 +49,7 @@ check_PROGRAMS = \
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test_rvalue_ref \
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test_scoped_connection \
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test_signal \
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test_signal_connect \
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test_signal_move \
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test_size \
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test_slot \
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test_rvalue_ref_SOURCES = test_rvalue_ref.cc $(sigc_test_util)
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test_scoped_connection_SOURCES = test_scoped_connection.cc $(sigc_test_util)
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test_signal_SOURCES = test_signal.cc $(sigc_test_util)
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test_signal_connect_SOURCES = test_signal_connect.cc $(sigc_test_util)
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test_signal_move_SOURCES = test_signal_move.cc $(sigc_test_util)
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test_size_SOURCES = test_size.cc $(sigc_test_util)
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test_slot_SOURCES = test_slot.cc $(sigc_test_util)

‎tests/meson.build

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[[], 'test_rvalue_ref', ['test_rvalue_ref.cc', 'testutilities.cc']],
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[[], 'test_scoped_connection', ['test_scoped_connection.cc', 'testutilities.cc']],
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[[], 'test_signal', ['test_signal.cc', 'testutilities.cc']],
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[[], 'test_signal_connect', ['test_signal_connect.cc', 'testutilities.cc']],
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[[], 'test_signal_move', ['test_signal_move.cc', 'testutilities.cc']],
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[[], 'test_size', ['test_size.cc', 'testutilities.cc']],
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[[], 'test_slot', ['test_slot.cc', 'testutilities.cc']],

‎tests/test_signal_connect.cc

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/* Copyright 2024, The libsigc++ Development Team
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* Assigned to public domain. Use as you wish without restriction.
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*/
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#include "testutilities.h"
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#include <sigc++/trackable.h>
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#include <sigc++/signal_connect.h>
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namespace
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{
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TestUtilities* util = nullptr;
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std::ostringstream result_stream;
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void
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fun(int i)
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{
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result_stream << "fun(int " << i << ")";
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}
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[[maybe_unused]]
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void
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fun(double d)
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{
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result_stream << "fun(double " << d << ")";
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}
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struct foo : public sigc::trackable
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{
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void fun_nonconst(int i)
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{
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result_stream << "foo::fun_nonconst(int " << i << ")";
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}
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void fun_nonconst(double d)
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{
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result_stream << "foo::fun_nonconst(double " << d << ")";
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}
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void fun_const(int i) const
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{
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result_stream << "foo::fun_const(int " << i << ")";
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}
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void fun_const(double d) const
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{
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result_stream << "foo::fun_const(double " << d << ")";
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}
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};
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struct bar : public sigc::trackable
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{
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void fun_nonconst(int i, int j)
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{
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result_stream << "bar::fun_nonconst(int " << i << ", int " << j << ")";
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}
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void fun_nonconst(int i, double j)
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{
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result_stream << "bar::fun_nonconst(int " << i << ", double " << j << ")";
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}
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void fun_const(int i, int j) const
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{
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result_stream << "bar::fun_const(int " << i << ", int " << j << ")";
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}
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void fun_const(int i, double j) const
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{
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result_stream << "bar::fun_const(int " << i << ", double " << j << ")";
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}
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};
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void
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test_signal_connect_fun()
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{
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sigc::signal<void(int)> signal;
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sigc::signal_connect(signal, &fun);
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signal.emit(42);
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util->check_result(result_stream, "fun(int 42)");
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}
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void
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test_signal_connect_method_nonconst()
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{
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sigc::signal<void(int)> signal;
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foo f;
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sigc::signal_connect(signal, f, &foo::fun_nonconst);
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signal.emit(42);
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util->check_result(result_stream, "foo::fun_nonconst(int 42)");
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}
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void
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test_signal_connect_method_const()
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{
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sigc::signal<void(int)> signal;
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foo f;
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sigc::signal_connect(signal, f, &foo::fun_const);
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signal.emit(42);
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util->check_result(result_stream, "foo::fun_const(int 42)");
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}
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void
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test_signal_connect_method_const_with_const_object()
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{
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sigc::signal<void(int)> signal;
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const foo f;
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sigc::signal_connect(signal, f, &foo::fun_const);
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signal.emit(42);
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util->check_result(result_stream, "foo::fun_const(int 42)");
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}
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void
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test_signal_connect_method()
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{
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test_signal_connect_method_nonconst();
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test_signal_connect_method_const();
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test_signal_connect_method_const_with_const_object();
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}
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} // end anonymous namespace
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int
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main(int argc, char* argv[])
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{
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util = TestUtilities::get_instance();
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if (!util->check_command_args(argc, argv))
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return util->get_result_and_delete_instance() ? EXIT_SUCCESS : EXIT_FAILURE;
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test_signal_connect_fun();
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test_signal_connect_method();
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return util->get_result_and_delete_instance() ? EXIT_SUCCESS : EXIT_FAILURE;
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}

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