C++ named requirements: TimedLockable
From cppreference.com
                    
                                        
                    
                    
                                                            
                    The TimedLockable requirements describe the characteristics of types that provide timed exclusive blocking semantics for execution agents (threads, processes, tasks).
Requirements
For type L to be TimedLockable, the following conditions have to be satisfied for an object m of type L:
| Expression | Requires | Return value | 
|---|---|---|
| m.try_lock_for(duration) | Blocks for the provided duration or until a lock on mis acquired. | true if the lock was acquired, false otherwise. | 
| m.try_lock_until(time_limit) | Blocks until the provided time limit point is reached or a lock on mis acquired. | true if the lock was acquired, false otherwise. |