Implicit return of last expression doesn't work

[boggle]

According to the tutorial, fn foo()->int { 7 } should be equivalent to fn foo()->int { ret 7; }. However, rustc right now rejects such function definitions.

[brson]

fn foo()->int { 7 } works for me. Indeed this is style of function is used frequently in rust. Maybe there is more to the error you are seeing.

[boggle]

The line in question was

   let g = vec::init_fn({|_i| ret vec::init_elt_mut(0 as u8, 10u); }, 10u);

Removing the ret gave type errors further down the function ("the type of this value must be known in this context"). I was blaming the ret. Adding an explicit type to g (still no ret) gives "In function anon, not all control paths return a value". Turns out that the trailing ";" is the cultprit, although I don't see why, and

let g = vec::init_fn({|_i| vec::init_elt_mut(0 as u8, 10u) }, 10u);

just works fine (no ret, no ; in the block) and doesn't require an explicit type annotation.

[lht]

I think this is covered in the expression syntax section of the tutorial

[boggle]

so it becomes nil. Well, a better error message or perhaps a warning would be nice in such cases.

[brson]

I think pcwalton proposed at some point a way to make the trailing semi optional. I've heard a few complaints about this syntax. A warning would definitely be useful. I'll open another issue for that.