Using without String/alloc

[transbitch]

Is there any support without using String? As I see it you don't need String for anything, you can just use core::fmt::Write. Would eliminate the need for an allocator

[lambda-fairy]

I remember experimenting with this in the past, but the extra Result param made codegen slightly worse. Might be worth checking if that factor still applies now.

[lambda-fairy]

Another consideration. With context-aware escaping, we might want to censor values after they're built – see the #ZgotmplZ example in html/template. It would be difficult to implement this without an intermediate buffer.