Retrieve the return type of the current function

[learner]

On Wednesday, 6 May 2020 at 08:04:16 UTC, Jacob Carlborg wrote:
> On 2020-05-05 19:11, learner wrote:
>> On Tuesday, 5 May 2020 at 16:41:06 UTC, Adam D. Ruppe wrote:
>> 
>>> typeof(return)
>> 
>> Thank you, that was indeed easy!
>> 
>> Is it possible to retrieve also the caller return type? 
>> Something like:
>
> Yes, kind of:
>
> void foo(string caller = __FUNCTION__)()
> {
>     import std.traits : ReturnType;
>
>     alias R = ReturnType!(mixin(caller));
>     static assert(is(R == int));
> }
>
> int bar()
> {
>     foo();
>     return 0;
> }

Awesome and beautiful, thank you!