https://stackoverflow.com/questions/1008019/c-singleton-design-pattern#
// C++ 03
class S03
{
public:
static S03& getInstance()
{
static S03 instance; // Guaranteed to be destroyed. Instantiated on first use.
return instance;
}
private:
S03() {} // Constructor? (the {} brackets) are needed here.
// C++ 03
// ========
// Don't forget to declare these two. You want to make sure they are unacceptable
// otherwise you may accidentally get copies of your singleton appearing.
S03(S03 const&); // Don't Implement
void operator=(S03 const&); // Don't implement
};
// C++ 11
class S11
{
public:
static S11& getInstance()
{
static S11 instance; // Guaranteed to be destroyed. Instantiated on first use.
return instance;
}
private:
S11() {} // Constructor? (the {} brackets) are needed here.
// C++ 11
// =======
// We can use the better technique of deleting the methods we don't want.
public:
S11(S11 const&) = delete;
void operator=(S11 const&) = delete;
// Note: Scott Meyers mentions in his Effective Modern
// C++ book, that deleted functions should generally
// be public as it results in better error messages
// due to the compilers behavior to check accessibility
// before deleted status
};
