57 lines
1.4 KiB
C++
57 lines
1.4 KiB
C++
//===-- MIUtilSingletonBase.h -----------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#pragma once
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namespace MI
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{
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// MI::ISingleton base class usage:
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//
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// class CMIDerivedClass
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// : public MI::ISingleton< CMIDerivedClass >
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// {
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// friend MI::ISingleton< CMIDerivedClass >;
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//
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// // Overridden:
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// public:
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// // From MI::ISingleton
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// bool Initialize() override;
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// bool Shutdown() override;
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// };
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//++ ============================================================================
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// Details: Base class for the singleton pattern.
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// Gotchas: Derived class must specify MI::ISingleton<> as a friend class.
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//--
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template <typename T> class ISingleton
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{
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// Statics:
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public:
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// Return an instance of the derived class
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static T &
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Instance()
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{
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// This will fail if the derived class has not
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// declared itself to be a friend of MI::ISingleton
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static T instance;
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return instance;
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}
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// Overrideable:
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public:
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virtual bool Initialize() = 0;
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virtual bool Shutdown() = 0;
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//
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/* dtor */ virtual ~ISingleton(){}
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};
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} // namespace MI
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