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#ifndef ERMYTH_PHOENIX_H |
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#define ERMYTH_PHOENIX_H |
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|
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#include <stdlib.h> // atexit() |
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|
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|
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namespace impl |
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{ |
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struct no_op_phoenix_initialiser |
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{ |
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template<typename T> |
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void operator () (T &) |
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{ |
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return; |
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} |
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}; |
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|
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template<typename BaseType, typename ContextType = BaseType, typename initialiserType = no_op_phoenix_initialiser> |
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struct phoenix : public BaseType |
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{ |
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typedef ContextType context_type; |
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typedef BaseType base_type; |
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typedef initialiserType initialiser_type; |
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|
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static base_type &instance () |
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{ |
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static this_type meyers; |
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static bool donethat = false; |
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|
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if (this_type::m_destroyed) |
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{ |
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// phoenix_CERR << "Phoenixing!" << std::endl; |
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donethat = false; |
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new (&meyers) this_type; |
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atexit (this_type::do_atexit); |
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} |
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|
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if (!donethat) |
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{ |
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// phoenix_CERR << "initialising instance" << std::endl; |
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donethat = true; |
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initialiser_type () (meyers); |
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} |
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|
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// phoenix_CERR << "instance() == " <<std::hex<<&meyers<<std::endl; |
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return meyers; |
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} |
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|
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private: |
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typedef phoenix<base_type,context_type,initialiser_type> this_type; |
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|
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static bool m_destroyed; |
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|
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phoenix () |
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{ |
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// phoenix_CERR << "phoenix() @" << std::hex<< this << std::endl; |
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m_destroyed = false; |
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} |
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|
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virtual ~phoenix () throw () |
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{ |
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// phoenix_CERR << "~phoenix() @" << std::hex<< this << std::endl; |
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m_destroyed = true; |
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} |
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|
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// Destroys the shared object via a manual call to it's dtor. |
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static void do_atexit() |
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{ |
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if (m_destroyed) |
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return; |
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// phoenix_CERR << "::do_atexit() @ " << std::hex << &instance() << std::endl; |
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static_cast<this_type &> (instance ()).~phoenix (); // will eventually trigger the BaseType dtor |
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} |
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}; |
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|
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template<typename T, typename C, typename I> |
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bool phoenix<T, C, I>::m_destroyed = false; |
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} // namespace |
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|
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#endif // ERMYTH_PHOENIX_H |
