Adding the ?. null verification

[logicchains via Digitalmars-d]

On Thursday, 19 June 2014 at 00:36:23 UTC, H. S. Teoh via 
Digitalmars-d wrote:
> I decided to run some tests on the compiled code to see how 
> performant
> However, with gdc -O3 -finline, all of the opDispatch calls got 
> inlined,
> and the assembly is the direct equivalent of:
>
> 	if (tree !is null)
> 		if (tree.left !is null)
> 			...
> 				writeln(tree.left.right. ... .val);
>

Somebody should blog on this or put it on the front page or 
something; how many other languages allow a cost-free maybe monad 
to be implemented in library code?