llvm-project/lldb/tools/lldb-mi/MIUtilSingletonBase.h

70 lines
1.6 KiB
C++

//===-- MIUtilSingletonBase.h -----------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//++
// File: MIUtilSingletonBase.h
//
// Overview: MI::ISingleton interface.
//
// Environment: Compilers: Visual C++ 12.
// gcc (Ubuntu/Linaro 4.8.1-10ubuntu9) 4.8.1
// Libraries: See MIReadmetxt.
//
// Copyright: None.
//--
#pragma once
namespace MI
{
// MI::ISingleton base class usage:
//
// class CMIDerivedClass
// : public MI::ISingleton< CMIDerivedClass >
// {
// friend MI::ISingleton< CMIDerivedClass >;
//
// // Overridden:
// public:
// // From MI::ISingleton
// virtual bool Initialize( void );
// virtual bool Shutdown( void );
// };
//++ ============================================================================
// Details: Base class for the singleton pattern.
// Gotchas: Derived class must specify MI::ISingleton<> as a friend class.
// Authors: Aidan Dodds 17/03/2014.
// Changes: None.
//--
template< typename T >
class ISingleton
{
// Statics:
public:
// Return an instance of the derived class
static T & Instance( void )
{
// 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( void ) = 0;
virtual bool Shutdown( void ) = 0;
//
/* dtor */ virtual ~ISingleton( void ) { };
};
} // namespace MI