once_flag Structure

Represents a struct that is used with the template function call_once to ensure that initialization code is called only once, even in the presence of multiple threads of execution.

Syntax

struct once_flag
{
   constexpr once_flag() noexcept;
};

Remarks

The once_flag struct has only a default constructor.

Objects of type once_flag can be created, but they cannot be copied.

Requirements

Header: <mutex>

Namespace: std

See also

Header Files Reference
<mutex>