Begin executing the specified invokable functor in a new thread, using the optionally specified thread attributes. Return 0 on success, and a non-zero value otherwise. INVOKABLE shall be a copy-constructible type having the equivalent of void operator()(). Note that threads are always created joinable, regardless of the mode specified in attributes.
Declared in <bslmt_threadgroup.h>
template<class INVOKABLE>
int
addThread(INVOKABLE const& functor);