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/* |
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callback.h -- C++ callback mechanism |
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|
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This program 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 this program; 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 VPE_CALLBACK_H__ |
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#define VPE_CALLBACK_H__ |
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|
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template<class R, class A> |
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class callback { |
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struct object { }; |
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|
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void *obj; |
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R (object::*meth)(A arg); |
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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)(A), A arg) = 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)(A), A arg) |
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{ |
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((reinterpret_cast<O1 *>(obj)) ->* (reinterpret_cast<R (O2::*)(A)>(meth))) |
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(arg); |
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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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callback (O1 *object, R (O2::*method)(A)) |
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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::*)(A)>(method); |
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prxy = &p; |
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} |
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|
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R call(A arg) const |
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{ |
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return prxy->call (obj, meth, arg); |
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} |
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|
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R operator ()(A arg) const |
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{ |
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return call (arg); |
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} |
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}; |
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|
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#endif |
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