30 Thread support library [thread]

30.3 Threads [thread.threads]

30.3.1 Class thread [thread.thread.class] thread constructors [thread.thread.constr]

thread() noexcept;

Effects: Constructs a thread object that does not represent a thread of execution.

Postcondition: get_id() == id()

template <class F, class ...Args> explicit thread(F&& f, Args&&... args);

Requires: F and each Ti in Args shall satisfy the MoveConstructible requirements. INVOKE(DECAY_COPY( std::forward<F>(f)), DECAY_COPY(std::forward<Args>(args))...) ([func.require]) shall be a valid expression.

Effects: Constructs an object of type thread. The new thread of execution executes INVOKE(DECAY_COPY( std::forward<F>(f)), DECAY_COPY(std::forward<Args>(args))...) with the calls to DECAY_COPY being evaluated in the constructing thread. Any return value from this invocation is ignored. [ Note: This implies that any exceptions not thrown from the invocation of the copy of f will be thrown in the constructing thread, not the new thread.  — end note ] If the invocation of INVOKE(DECAY_COPY( std::forward<F>(f)), DECAY_COPY(std::forward<Args>(args))...) terminates with an uncaught exception, std::terminate shall be called.

Synchronization: The completion of the invocation of the constructor synchronizes with the beginning of the invocation of the copy of f.

Postconditions: get_id() != id(). *this represents the newly started thread.

Throws: system_error if unable to start the new thread.

Error conditions:

  • resource_unavailable_try_again — the system lacked the necessary resources to create another thread, or the system-imposed limit on the number of threads in a process would be exceeded.

thread(thread&& x) noexcept;

Effects: Constructs an object of type thread from x, and sets x to a default constructed state.

Postconditions: x.get_id() == id() and get_id() returns the value of x.get_id() prior to the start of construction.