match_like_matches_macro macro gets expanded in suggestion when matching on macro #16015
Description
Using the following flags
--force-warn clippy::match_like_matches_macro
this code:
use std::any::{type_name, TypeId};
pub struct GetTypeId<T>(T);
impl<T: 'static> GetTypeId<T> {
pub const VALUE: TypeId = TypeId::of::<T>();
}
#[macro_export]
macro_rules! typeid {
($t:ty) => {
$crate::GetTypeId::<$t>::VALUE
};
}
const fn same_type<T: 'static, U: 'static>() -> bool {
match typeid!(T) {
_ => true,
_ => false,
}
}
fn print_if_equal<T: 'static, U: 'static>() {
if same_type::<T, U>() {
println!("{} == {}", type_name::<T>(), type_name::<U>());
} else {
}
}
fn main() {
print_if_equal::<usize, u32>();
print_if_equal::<usize, usize>();
}caused the following diagnostics:
Checking _45049dfa6ff33ebd29f080109ea274f8636bfbb6 v0.1.0 (/tmp/icemaker_global_tempdir.tMrpGeJ6WWUI/icemaker_clippyfix_tempdir.X6Ai7ihNEVse/_45049dfa6ff33ebd29f080109ea274f8636bfbb6)
warning: match expression looks like `matches!` macro
--> src/main.rs:18:5
|
18 | / match typeid!(T) {
19 | | _ => true,
20 | | _ => false,
21 | | }
| |_____^ help: try: `matches!($crate::GetTypeId::<$t>::VALUE, _)`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_like_matches_macro
= note: requested on the command line with `--force-warn clippy::match-like-matches-macro`
warning: `_45049dfa6ff33ebd29f080109ea274f8636bfbb6` (bin "_45049dfa6ff33ebd29f080109ea274f8636bfbb6") generated 1 warning
Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.22s
However after applying these diagnostics, the resulting code:
use std::any::{type_name, TypeId};
pub struct GetTypeId<T>(T);
impl<T: 'static> GetTypeId<T> {
pub const VALUE: TypeId = TypeId::of::<T>();
}
#[macro_export]
macro_rules! typeid {
($t:ty) => {
$crate::GetTypeId::<$t>::VALUE
};
}
const fn same_type<T: 'static, U: 'static>() -> bool {
matches!($crate::GetTypeId::<$t>::VALUE, _)
}
fn print_if_equal<T: 'static, U: 'static>() {
if same_type::<T, U>() {
println!("{} == {}", type_name::<T>(), type_name::<U>());
} else {
}
}
fn main() {
print_if_equal::<usize, u32>();
print_if_equal::<usize, usize>();
}no longer compiled:
Checking _45049dfa6ff33ebd29f080109ea274f8636bfbb6 v0.1.0 (/tmp/icemaker_global_tempdir.tMrpGeJ6WWUI/icemaker_clippyfix_tempdir.X6Ai7ihNEVse/_45049dfa6ff33ebd29f080109ea274f8636bfbb6)
error: no rules expected `$`
--> src/main.rs:18:14
|
18 | matches!($crate::GetTypeId::<$t>::VALUE, _)
| ^ no rules expected this token in macro call
|
note: while trying to match meta-variable `$expression:expr`
--> /home/matthias/.rustup/toolchains/master/lib/rustlib/src/rust/library/core/src/macros/mod.rs:435:6
|
435 | ($expression:expr, $pattern:pat $(if $guard:expr)? $(,)?) => {
| ^^^^^^^^^^^^^^^^
error: could not compile `_45049dfa6ff33ebd29f080109ea274f8636bfbb6` (bin "_45049dfa6ff33ebd29f080109ea274f8636bfbb6" test) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: could not compile `_45049dfa6ff33ebd29f080109ea274f8636bfbb6` (bin "_45049dfa6ff33ebd29f080109ea274f8636bfbb6") due to 1 previous error
Version:
rustc 1.93.0-nightly (6a884ad1b 2025-11-02)
binary: rustc
commit-hash: 6a884ad1b502fe48307d363858510702429fc735
commit-date: 2025-11-02
host: x86_64-unknown-linux-gnu
release: 1.93.0-nightly
LLVM version: 21.1.3