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|
#![warn(clippy::collapsible_match)]
#![allow(
clippy::needless_return,
clippy::no_effect,
clippy::single_match,
clippy::needless_borrow
)]
fn lint_cases(opt_opt: Option<Option<u32>>, res_opt: Result<Option<u32>, String>) {
// if guards on outer match
{
match res_opt {
Ok(val) if make() => match val {
Some(n) => foo(n),
_ => return,
},
_ => return,
}
match res_opt {
Ok(val) => match val {
Some(n) => foo(n),
_ => return,
},
_ if make() => return,
_ => return,
}
}
// macro
{
macro_rules! mac {
($outer:expr => $pat:pat, $e:expr => $inner_pat:pat, $then:expr) => {
match $outer {
$pat => match $e {
$inner_pat => $then,
_ => return,
},
_ => return,
}
};
}
// Lint this since the patterns are not defined by the macro.
// Allows the lint to work on if_chain! for example.
// Fixing the lint requires knowledge of the specific macro, but we optimistically assume that
// there is still a better way to write this.
mac!(res_opt => Ok(val), val => Some(n), foo(n));
}
// deref reference value
match Some(&[1]) {
Some(s) => match *s {
[n] => foo(n),
_ => (),
},
_ => (),
}
// ref pattern and deref
match Some(&[1]) {
Some(ref s) => match s {
[n] => foo(n),
_ => (),
},
_ => (),
}
}
fn no_lint() {
// deref inner value (cannot pattern match with Vec)
match Some(vec![1]) {
Some(s) => match *s {
[n] => foo(n),
_ => (),
},
_ => (),
}
}
fn make<T>() -> T {
unimplemented!()
}
fn foo<T, U>(t: T) -> U {
unimplemented!()
}
fn main() {}
|
