Sometimes, it may be necessary to call the member function trylock on a mutex. The safe and unsafe mutexes may be created with trylock enabled by passing a Boolean value to the mutex constructor as shown below:

Since inter-process mutexes are required on certain machines to support the trylock, the function trylock is specified in the constructor —for example, on Windows®. Using the trylock functionality on machines where an inter-process mutex is used seriously degrades the performance of the member functions lock and unlock.