Single-element vec / str append. #44
Description
This might involve digging in the typechecker a bit; it'd be good for these to
work:
let vec[T] v = ...;
let T t = ...;
v += t;
and
let str s = "hi";
s += 'x';
At the moment both the typechecker and the backend prefer to think of operator
- as only applying to identical-typed values. Which is usually good. This is
just an exceptional case that might be good to provide support for.
For the time being we can fake it using a single-element temporary vec or a
single-char string. It's just kinda lame. But this is a lower-priority bug.