constexpr adopt_lock_t adopt_lock {};
Adopt lock
Value used as possible argument to the constructor of unique_lock or lock_guard.

unique_lock objects constructed with adopt_lock do not lock the mutex object on construction, assuming instead that it is already locked by the current thread.

The value is a compile-time constant that carries no state, and is merely used to disambiguate between constructor signatures.

adopt_lock_t is an empty class.

See also