loops can break with a value
loops can now break with a value:
#![allow(unused_variables)] fn main() { // old code let x; loop { x = 7; break; } // new code let x = loop { break 7; }; }
Rust has traditionally positioned itself as an “expression oriented
language”, that is, most things are expressions that evaluate to a value,
rather than statements. loop stuck out as strange in this way, as it was
previously a statement.
For now, this only applies to loop, and not things like while or for.
See the rationale for this decision in RFC issue #1767.