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concat!() rejects negative number literal #106837
Description
I tried this code:
fn main() {
println!("{}", concat!(-1));
}I expected to see this happen: code compiles.
Since the following code compiles:
macro_rules! t {
($item: literal) => { stringify!($item) }
}
fn main() {
println!("{}", t!(-1));
}The macro system recognizes -1 as a single literal in this case.
Instead, this happened:
error: expected a literal
--> src/main.rs:2:28
|
2 | println!("{}", concat!(-1));
| ^^
|
= note: only literals (like `"foo"`, `42` and `3.14`) can be passed to `concat!()`
error: could not compile `playground` due to previous error
Meta
rustc --version --verbose:
Tried on playground, all channels:
Stable 1.66.1
Beta 1.67.0-beta.7 (2023-01-11 275123c)
Nightly 1.68.0-nightly (2023-01-13 0b90256)
Backtrace
Activity
Ezrashaw commentedon Jan 14, 2023
Hmm, this actually looks like fun to fix.
@rustbot claim
Rollup merge of rust-lang#106844 - Ezrashaw:concat-negative-int-lit, …
Rollup merge of rust-lang#106844 - Ezrashaw:concat-negative-int-lit, …