std::atomic是否保证int、float等类型初始化为0/0.0？

Question

std::atomic<basic_type> 是否保证 basic_type 的值在创建为 class 成员时为 0 / 0.0（以适用者为准）而未明确初始化为：

int / uint / short / ushort / 等...
和；浮动/双

?

示例：

class Foo
{
public:
    std::atomic<int> bar;
};

int main()
{
    Foo foo;
    return foo.bar; //foo.bar guaranteed to be 0?
}

Answer 1

来自 std::atomic default constructor 的 cppreference 文档：

The default constructor is trivial: no initialization takes place other than zero initialization of static and thread-local objects. std::atomic_init may be used to complete initialization.

因此，在您的情况下，您将获得与简单声明相同的保证 int bar;

std::atomic是否保证int、float等类型初始化为0/0.0？

Does std::atomic guarantee initialization initialization of types like int, float etc to 0/0.0?

initialization

c++11

stdatomic