54 lines
965 B
C
54 lines
965 B
C
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#pragma once
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#include "common/IErrors.h"
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#pragma warning(push)
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#pragma warning(disable: 4311 4312)
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/**
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* A singleton base class
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*
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* Singletons are useful when you have a class that will be instantiated once,
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* like a global manager.
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*/
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template <typename T>
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class ISingleton
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{
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static T * ms_Singleton;
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public:
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ISingleton()
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{
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ASSERT(!ms_Singleton);
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intptr_t offset = (intptr_t)(T *)1 - (intptr_t)(ISingleton <T> *)(T *)1;
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ms_Singleton = (T *)((intptr_t)this + offset);
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}
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virtual ~ISingleton()
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{
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ASSERT(ms_Singleton);
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ms_Singleton = 0;
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}
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/**
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* Returns the single instance of the derived class
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*/
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static T& GetSingleton(void)
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{
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ASSERT(ms_Singleton);
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return *ms_Singleton;
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}
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/**
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* Returns a pointer to the single instance of the derived class
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*/
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static T * GetSingletonPtr(void)
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{
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return ms_Singleton;
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}
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};
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template <typename T> T * ISingleton <T>::ms_Singleton = 0;
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#pragma warning(pop)
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