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|
#![warn(clippy::if_then_some_else_none)]
#![allow(clippy::redundant_pattern_matching, clippy::unnecessary_lazy_evaluations)]
fn main() {
// Should issue an error.
let _ = if foo() {
//~^ if_then_some_else_none
println!("true!");
Some("foo")
} else {
None
};
// Should issue an error when macros are used.
let _ = if matches!(true, true) {
//~^ if_then_some_else_none
println!("true!");
Some(matches!(true, false))
} else {
None
};
// Should issue an error. Binary expression `o < 32` should be parenthesized.
let x = Some(5);
let _ = x.and_then(|o| if o < 32 { Some(o) } else { None });
//~^ if_then_some_else_none
// Should issue an error. Unary expression `!x` should be parenthesized.
let x = true;
let _ = if !x { Some(0) } else { None };
//~^ if_then_some_else_none
// Should not issue an error since the `else` block has a statement besides `None`.
let _ = if foo() {
println!("true!");
Some("foo")
} else {
eprintln!("false...");
None
};
// Should not issue an error since there are more than 2 blocks in the if-else chain.
let _ = if foo() {
println!("foo true!");
Some("foo")
} else if bar() {
println!("bar true!");
Some("bar")
} else {
None
};
let _ = if foo() {
println!("foo true!");
Some("foo")
} else {
bar().then(|| {
println!("bar true!");
"bar"
})
};
// Should not issue an error since the `then` block has `None`, not `Some`.
let _ = if foo() { None } else { Some("foo is false") };
// Should not issue an error since the `else` block doesn't use `None` directly.
let _ = if foo() { Some("foo is true") } else { into_none() };
// Should not issue an error since the `then` block doesn't use `Some` directly.
let _ = if foo() { into_some("foo") } else { None };
}
#[clippy::msrv = "1.49"]
fn _msrv_1_49() {
// `bool::then` was stabilized in 1.50. Do not lint this
let _ = if foo() {
println!("true!");
Some(149)
} else {
None
};
}
#[clippy::msrv = "1.50"]
fn _msrv_1_50() {
let _ = if foo() {
//~^ if_then_some_else_none
println!("true!");
Some(150)
} else {
None
};
}
fn foo() -> bool {
unimplemented!()
}
fn bar() -> bool {
unimplemented!()
}
fn into_some<T>(v: T) -> Option<T> {
Some(v)
}
fn into_none<T>() -> Option<T> {
None
}
// Should not warn
fn f(b: bool, v: Option<()>) -> Option<()> {
if b {
v?; // This is a potential early return, is not equivalent with `bool::then`
Some(())
} else {
None
}
}
fn issue11394(b: bool, v: Result<(), ()>) -> Result<(), ()> {
let x = if b {
#[allow(clippy::let_unit_value)]
let _ = v?;
Some(())
} else {
None
};
Ok(())
}
fn issue13407(s: &str) -> Option<bool> {
if s == "1" { Some(true) } else { None }
//~^ if_then_some_else_none
}
const fn issue12103(x: u32) -> Option<u32> {
// Should not issue an error in `const` context
if x > 42 { Some(150) } else { None }
}
mod issue15257 {
struct Range {
start: u8,
end: u8,
}
fn can_be_safely_rewrite(rs: &[&Range]) -> Option<Vec<u8>> {
if rs.len() == 1 && rs[0].start == rs[0].end {
//~^ if_then_some_else_none
Some(vec![rs[0].start])
} else {
None
}
}
fn reborrow_as_ptr(i: *mut i32) -> Option<*const i32> {
let modulo = unsafe { *i % 2 };
if modulo == 0 {
//~^ if_then_some_else_none
Some(i)
} else {
None
}
}
fn reborrow_as_fn_ptr(i: i32) {
fn do_something(fn_: Option<fn(i32)>) {
todo!()
}
fn item_fn(i: i32) {
todo!()
}
do_something(if i % 2 == 0 {
//~^ if_then_some_else_none
Some(item_fn)
} else {
None
});
}
fn reborrow_as_fn_unsafe(i: i32) {
fn do_something(fn_: Option<unsafe fn(i32)>) {
todo!()
}
fn item_fn(i: i32) {
todo!()
}
do_something(if i % 2 == 0 {
//~^ if_then_some_else_none
Some(item_fn)
} else {
None
});
let closure_fn = |i: i32| {};
do_something(if i % 2 == 0 {
//~^ if_then_some_else_none
Some(closure_fn)
} else {
None
});
}
}
fn issue15005() {
struct Counter {
count: u32,
}
impl Counter {
fn new() -> Counter {
Counter { count: 0 }
}
}
impl Iterator for Counter {
type Item = u32;
fn next(&mut self) -> Option<Self::Item> {
//~v if_then_some_else_none
if self.count < 5 {
self.count += 1;
Some(self.count)
} else {
None
}
}
}
}
fn statements_from_macro() {
macro_rules! mac {
() => {
println!("foo");
println!("bar");
};
}
//~v if_then_some_else_none
let _ = if true {
mac!();
Some(42)
} else {
None
};
}
fn dont_lint_inside_macros() {
macro_rules! mac {
($cond:expr, $res:expr) => {
if $cond { Some($res) } else { None }
};
}
let _: Option<u32> = mac!(true, 42);
}
|
