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std::once_flag

From cppreference.com
Defined in header <mutex>
class once_flag;
(since C++11)

The class std::once_flag is a helper structure passed to std::call_once to group invocations of that function so that only one invocation results in execution of one of the functions passed to std::call_once.

Noncopyable.

Contents

[edit] Member functions

std::once_flag::once_flag

once_flag();

Constructs an once_flag object. The internal state is set to indicate that no function has been called yet.

Parameters

(none)

Exceptions

noexcept specification:  
noexcept
  (since C++11)

[edit] See also

(C++11)
invokes a function only once even if called from multiple threads
(function template) [edit]