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