Concept proposal: Safely catching error

[Stanislav Blinov via Digitalmars-d]

On Thursday, 8 June 2017 at 14:13:53 UTC, Steven Schveighoffer 
wrote:

> void foo(Mutex m, Data d) pure
> {
>    synchronized(m)
>    {
>    	// ... manipulate d
>    } // no guarantee m gets unlocked
> }
>
> -Steve

Isn't synchronized(m) not nothrow?