Auto merge of #79817 - LingMan:if_map, r=lcnr

Replace simple `if let` constructs with Option::map

Replaces a few constructs of the form

```
if let Some(x) = var {
    Some(...)
} else {
    None
}
```

with calls to `Option::map`.

`@rustbot` modify labels +C-cleanup +T-compiler
This commit is contained in:
bors 2020-12-08 13:58:15 +00:00
commit 5e6e1e33a1

View file

@ -361,11 +361,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
fn replace_prefix(&self, s: &str, old: &str, new: &str) -> Option<String> {
if let Some(stripped) = s.strip_prefix(old) {
Some(new.to_string() + stripped)
} else {
None
}
s.strip_prefix(old).map(|stripped| new.to_string() + stripped)
}
/// This function is used to determine potential "simple" improvements or users' errors and
@ -587,47 +583,23 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
hir::Mutability::Mut => {
let new_prefix = "&mut ".to_owned() + derefs;
match mutbl_a {
hir::Mutability::Mut => {
if let Some(s) =
self.replace_prefix(&src, "&mut ", &new_prefix)
{
Some((s, Applicability::MachineApplicable))
} else {
None
}
}
hir::Mutability::Not => {
if let Some(s) =
self.replace_prefix(&src, "&", &new_prefix)
{
Some((s, Applicability::Unspecified))
} else {
None
}
}
hir::Mutability::Mut => self
.replace_prefix(&src, "&mut ", &new_prefix)
.map(|s| (s, Applicability::MachineApplicable)),
hir::Mutability::Not => self
.replace_prefix(&src, "&", &new_prefix)
.map(|s| (s, Applicability::Unspecified)),
}
}
hir::Mutability::Not => {
let new_prefix = "&".to_owned() + derefs;
match mutbl_a {
hir::Mutability::Mut => {
if let Some(s) =
self.replace_prefix(&src, "&mut ", &new_prefix)
{
Some((s, Applicability::MachineApplicable))
} else {
None
}
}
hir::Mutability::Not => {
if let Some(s) =
self.replace_prefix(&src, "&", &new_prefix)
{
Some((s, Applicability::MachineApplicable))
} else {
None
}
}
hir::Mutability::Mut => self
.replace_prefix(&src, "&mut ", &new_prefix)
.map(|s| (s, Applicability::MachineApplicable)),
hir::Mutability::Not => self
.replace_prefix(&src, "&", &new_prefix)
.map(|s| (s, Applicability::MachineApplicable)),
}
}
} {