C++11

// <atomic> ​
​// 类模板(1)    
template <class T> void atomic_init (volatile atomic<T>* obj, T val) noexcept;
template <class T> void atomic_init (atomic<T>* obj, T val) noexcept;
// 重载(2)    
void atomic_init (volatile A* obj, T val) noexcept;
void atomic_init (A* obj, T val) noexcept;

默认构造(Default-constructed)的原子对象的非原子初始化(Non-atomic initialization)