Better string mixins

[Dgame]

On Wednesday, 2 January 2019 at 21:06:19 UTC, Bastiaan Veelo 
wrote:
> On Wednesday, 2 January 2019 at 18:59:53 UTC, Dgame wrote:
>> Hi, I've played around with string interpolation and wanted to 
>> ask if this is somewhat helpful?
>>
>> https://run.dlang.io/is/6AokiH
>
> You are aware of `writefln`?
>
>>    writeln(fmt!("a = $a, b = $b, c = $c", a, b, c));
>>    writefln("a = %s, b = %s, c = %s", a, b, c);
>
> These lines produce the same output.

Yes I do. But consider this:

int c = 3;
int z = c * c;

writefln("%s * %s = %s", c, c, z);

vs

writeln(fmt!("$c * $c = $z", c, z));

Just one c is applied. But I've disovered one slightly error 
here, the interpolation variables should be enclosed with { to 
prevent mistakenly replacement.

Also, currently no further "magic" as ${c * 2} can't be 
interpreted as someone might wish, it is somewhat static, but 
I've thought it might be interesting.