Unlike expr macros, macros in type position in a derive input are rare
enough that it's not worth supporting for an issue that has such an easy
workaround (just replace `Self` in the macro input with your type name).
I think there is no ambiguity in from_str as a method name so "choose a
less ambiguous method name" is unnecessary, and it can't be a FromStr
impl in this case because FromStr's error type cannot borrow from the
input string slice.
warning: method `from_str` can be confused for the standard trait method `std::str::FromStr::from_str`
--> serde_derive_internals/src/case.rs:50:5
|
50 | / pub fn from_str(rename_all_str: &str) -> Result<Self, ParseError> {
51 | | for (name, rule) in RENAME_RULES {
52 | | if rename_all_str == *name {
53 | | return Ok(*rule);
... |
58 | | })
59 | | }
| |_____^
|
= note: `#[warn(clippy::should_implement_trait)]` on by default
= help: consider implementing the trait `std::str::FromStr` or choosing a less ambiguous method name
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#should_implement_trait
This usage is fine. It's mirroring trait signatures in syn::visit::Visit.
error: unused `self` argument
--> serde_derive/src/bound.rs:241:24
|
241 | fn visit_macro(&mut self, _mac: &'ast syn::Macro) {}
| ^^^^^^^^^
|
note: the lint level is defined here
--> serde_derive/src/lib.rs:18:22
|
18 | #![deny(clippy::all, clippy::pedantic)]
| ^^^^^^^^^^^^^^^^
= note: `#[deny(clippy::unused_self)]` implied by `#[deny(clippy::pedantic)]`
= help: consider refactoring to a associated function
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unused_self
The builtin visitor is fairly expensive to compile (3700 lines of code),
particularly if something else in the dependency graph also enables
syn/full. For the usage in serde_derive, it turns out to be easy to
replace.
The implied lifetime bound on T only works on 1.31+. Older versions fail
with:
error[E0309]: the parameter type `T` may not live long enough
--> serde/src/private/de.rs:2548:37
|
2548 | pub struct Borrowed<'de, T: ?Sized>(pub &'de T);
| -- ^^^^^^^^^^
| |
| help: consider adding an explicit lifetime bound `T: 'de`...
|
note: ...so that the reference type `&'de T` does not outlive the data it points at
--> serde/src/private/de.rs:2548:37
|
2548 | pub struct Borrowed<'de, T: ?Sized>(pub &'de T);
| ^^^^^^^^^^
The BorrowedDeserializer was added in #1917, but only makes sense for
&str and &[u8], not for u64 which also needs to be have an
IdentifierDeserializer impl.
