Interpolated strings

[Nick Treleaven via Digitalmars-d]

On Thursday, 20 April 2017 at 21:34:44 UTC, Steven Schveighoffer 
wrote:
> Dmitry's solution is superior I think:
>
> $"{a} times 3 is {a * 3}"
>
> ->
>
> AliasSeq!(a, " times 3 is ", a * 3)

+1, this is more flexible.

> Would work fine with writeln.

Yep, and std.conv.text. We might want a function that takes the 
quoted AliasSeq expansion and writes it to an output range.

> Would work fine with format.

No, std.format.format needs a format string as first argument, 
supplying extra arguments will not work.

I like how this expansion *always* parses the string at 
compile-time. The expansion could be passed whole as template 
arguments if desired - I think this would allow text!(seq) which, 
if passed only literal strings and runtime scalar types, can 
return a fixed size static array, even though the scalar values 
are read and formatted at runtime.