mirror of
https://github.com/rust-lang/rust.git
synced 2026-05-16 13:05:18 +03:00
Samuel Tardieu
951d35eeb6
Starting with Rust version 1.82.0, the compiler generates similar code with
and without the `with_ref` cfg:
```rust
fn f(x: impl IntoIterator<Item = String>) {
for y in x { println!("{y}"); }
}
fn main() {
#[cfg(with_ref)]
let a = ["foo", "bar"].iter().map(|&s| s.to_string());
#[cfg(not(with_ref))]
let a = ["foo", "bar"].iter().map(|s| s.to_string());
f(a);
}
```
The generated code is strictly identical with `-O`, and identical modulo
some minor reordering without.
45 lines
1.3 KiB
Rust
45 lines
1.3 KiB
Rust
#![deny(clippy::inefficient_to_string)]
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use std::borrow::Cow;
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#[clippy::msrv = "1.81"]
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fn main() {
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let rstr: &str = "hello";
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let rrstr: &&str = &rstr;
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let rrrstr: &&&str = &rrstr;
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let _: String = rstr.to_string();
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let _: String = (*rrstr).to_string();
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//~^ inefficient_to_string
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let _: String = (**rrrstr).to_string();
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//~^ inefficient_to_string
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let string: String = String::from("hello");
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let rstring: &String = &string;
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let rrstring: &&String = &rstring;
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let rrrstring: &&&String = &rrstring;
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let _: String = string.to_string();
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let _: String = rstring.to_string();
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let _: String = (*rrstring).to_string();
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//~^ inefficient_to_string
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let _: String = (**rrrstring).to_string();
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//~^ inefficient_to_string
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let cow: Cow<'_, str> = Cow::Borrowed("hello");
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let rcow: &Cow<'_, str> = &cow;
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let rrcow: &&Cow<'_, str> = &rcow;
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let rrrcow: &&&Cow<'_, str> = &rrcow;
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let _: String = cow.to_string();
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let _: String = rcow.to_string();
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let _: String = (*rrcow).to_string();
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//~^ inefficient_to_string
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let _: String = (**rrrcow).to_string();
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//~^ inefficient_to_string
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}
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#[clippy::msrv = "1.82"]
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fn sufficient_msrv() {
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let rstr: &str = "hello";
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let rrstr: &&str = &rstr;
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let _: String = rrstr.to_string();
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}
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