>>101204840
check mine
#pragma once
#include <cstdlib> // free, malloc
#include "meta/assert.h"
namespace stuff {
template<typename T>
class Singleton {
public:
static inline T& the()
{
if (s_instance == nullptr) {
// Allocate memory for this instance
s_instance = static_cast<T*>(malloc(sizeof(T)));
// Call the constructor using "placement new"
new (s_instance) T { s {} };
}
return *s_instance;
}
static inline void destroy()
{
if (!s_instance) {
return;
}
// Call the destructor
s_instance->~T();
// Deallocate memory
free(static_cast<void*>(s_instance));
s_instance = nullptr;
}
// Remove copy constructor and copy assignment operator
Singleton(const Singleton&) = delete;
Singleton& operator=(const Singleton&) = delete;
Singleton(Singleton&&) = delete;
Singleton& operator=(Singleton&&) = delete;
protected:
Singleton() {}
// Constructor token
struct s {};
private:
static T* s_instance;
};
template<typename T>
T* Singleton<T>::s_instance = nullptr;
} // namespace stuff
you use it like so
class MyClass : public stuff::Singleton<MyClass> {
public:
MyClass(s) {}
};
MyClass::the();
