rust/tests/ui/rfcs/rfc-2497-if-let-chains/ensure-that-let-else-does-not-interact-with-let-chains.rs
Matthew Jasper 333388fd3c Move let expression checking to parsing
There was an incomplete version of the check in parsing and a second
version in AST validation. This meant that some, but not all, invalid
uses were allowed inside macros/disabled cfgs. It also means that later
passes have a hard time knowing when the let expression is in a valid
location, sometimes causing ICEs.

- Add a field to ExprKind::Let in AST/HIR to mark whether it's in a
  valid location.
- Suppress later errors and MIR construction for invalid let
  expressions.
2023-09-11 15:51:18 +00:00

55 lines
1.4 KiB
Rust

#![feature(let_chains)]
fn main() {
let opt = Some(1i32);
let Some(n) = opt else {
return;
};
let Some(n) = opt && n == 1 else {
//~^ ERROR a `&&` expression cannot be directly assigned in `let...else`
//~| ERROR mismatched types
//~| ERROR mismatched types
return;
};
let Some(n) = opt && let another = n else {
//~^ ERROR a `&&` expression cannot be directly assigned in `let...else`
//~| ERROR mismatched types
//~| ERROR mismatched types
//~| ERROR expected expression, found `let` statement
return;
};
if let Some(n) = opt else {
//~^ ERROR this `if` expression is missing a block after the condition
return;
};
if let Some(n) = opt && n == 1 else {
//~^ ERROR this `if` expression is missing a block after the condition
return;
};
if let Some(n) = opt && let another = n else {
//~^ ERROR this `if` expression is missing a block after the condition
return;
};
{
while let Some(n) = opt else {
//~^ ERROR expected `{`, found keyword `else`
return;
};
}
{
while let Some(n) = opt && n == 1 else {
//~^ ERROR expected `{`, found keyword `else`
return;
};
}
{
while let Some(n) = opt && let another = n else {
//~^ ERROR expected `{`, found keyword `else`
return;
};
}
}