How is std.regex.replaceAllInto more efficient?

[Shriramana Sharma via Digitalmars-d]

Dmitry Olshansky wrote:

> My problem with it is writeln/byLine b/c it can't be unittested.
> Documented unit-tests as examples are gold.

That's true, but then the point was not to produce a valid unittest for the 
*Into functions but a meaningful *example*, which will make clear to a user 
how this function is useful, no?

-- 
Shriramana Sharma, Penguin #395953