False negatives on manual_map (regressions since 1.86) #16031
Description
Summary
Including references in the result value, and the presence of type annotations on the assignment both seem to have an effect on the detection.
Lint Name
manual_map
Reproducer
I tried this code:
#![allow(dead_code, unused)]
static TRUE: bool = true;
static FALSE: bool = false;
static STRINGS: [&str; 2] = ["hello", "hi"];
pub fn clippy_repo_auto_types(i: usize) {
let trimmed = if let Some(v) = STRINGS.get(i) {
Some(v.trim())
} else {
None
};
let len = if let Some(v) = STRINGS.get(i) {
Some(v.len())
} else {
None
};
let is_long = if let Some(v) = STRINGS.get(i) {
Some(if v.len() > 3 { &TRUE } else { &FALSE })
} else {
None
};
}
pub fn clippy_repro_explicit_types(i: usize) {
let trimmed: Option<&'static str> = if let Some(v) = STRINGS.get(i) {
Some(v.trim())
} else {
None
};
let len: Option<usize> = if let Some(v) = STRINGS.get(i) {
Some(v.len())
} else {
None
};
let is_long: Option<&'static bool> = if let Some(v) = STRINGS.get(i) {
Some(if v.len() > 3 { &TRUE } else { &FALSE })
} else {
None
};
}
pub fn clippy_repro_trim(i: usize) -> Option<&'static str> {
if let Some(v) = STRINGS.get(i) {
Some(v.trim())
} else {
None
}
}
pub fn clippy_repro_bool(i: usize) -> Option<&'static bool> {
if let Some(v) = STRINGS.get(i) {
Some(if v.len() > 3 { &TRUE } else { &FALSE })
} else {
None
}
}There are 8 occurrences which I believe break the manual_map rule.
On 1.90, we see 3 warnings: https://godbolt.org/z/KqTf7Gqjc
Going back to 1.86, there were 6 warnings: https://godbolt.org/z/nEx57EeoE
Seems like #14389 would match the timeline of a change made between 14 February, 2025 and 28 March, 2025.