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/* |
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callback.h -- C++ callback mechanism |
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Copyright (C) 2003-2018 Marc Lehmann <pcg@goof.com> |
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|
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Deliantra is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program 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 |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with gvpe; if not, write to the Free Software |
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Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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|
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#ifndef CALLBACK_H__ |
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#define CALLBACK_H__ |
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|
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template<typename signature> |
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class callback; |
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|
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template<typename R, typename ...Args> |
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class callback<R (Args...)> |
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{ |
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struct object { }; |
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|
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typedef R (object::*ptr_type)(Args...); |
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|
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void *obj; |
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R (object::*meth)(Args...); |
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|
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/* a proxy is a kind of recipe on how to call a specific class method */ |
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struct proxy_base { |
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virtual R call (void *obj, R (object::*meth)(Args...), Args... args) const = 0; |
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}; |
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template<class O1, class O2> |
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struct proxy : proxy_base { |
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virtual R call (void *obj, R (object::*meth)(Args...), Args... args) const |
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{ |
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return (R)((reinterpret_cast<O1 *>(obj)) ->* (reinterpret_cast<R (O2::*)(Args...)>(meth))) |
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(args...); |
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} |
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}; |
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|
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proxy_base *prxy; |
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|
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public: |
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template<class O1, class O2> |
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explicit callback (O1 *object, R (O2::*method)(Args...)) |
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{ |
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static proxy<O1,O2> p; |
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obj = reinterpret_cast<void *>(object); |
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meth = reinterpret_cast<R (object::*)(Args...)>(method); |
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prxy = &p; |
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} |
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|
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R call(Args... args) const |
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{ |
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return prxy->call (obj, meth, args...); |
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} |
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|
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R operator ()(Args... args) const |
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{ |
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return call (args...); |
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} |
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}; |
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|
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#endif |
