Deduce template arguments from return value?

[rsw0x via Digitalmars-d]

On Sunday, 12 July 2015 at 09:13:03 UTC, Yuxuan Shui wrote:
> For example:
> import std.conv;
> T a(T)(int a) {
> 	return to!T(a);
> }
> void main(){
> 	string x = a(2);
> }
>
> D is not able to deduce T. Can we make it possible to deduce 
> template arguments from where the return value is assigned to?

auto a(T)(int a) {
     return to!T(a);
}

?