Static RUST_2024_GUARDED_STRING_INCOMPATIBLE_SYNTAX 

pub static RUST_2024_GUARDED_STRING_INCOMPATIBLE_SYNTAX: &'static Lint

The rust_2024_guarded_string_incompatible_syntax lint detects # tokens that will be parsed as part of a guarded string literal in Rust 2024.

Example

#![deny(rust_2024_guarded_string_incompatible_syntax)]

macro_rules! m {
    (# $x:expr #) => ();
    (# $x:expr) => ();
}

m!(#"hey"#);
m!(#"hello");

{{produces}}

Explanation

Prior to Rust 2024, #"hey"# is three tokens: the first # followed by the string literal "hey" then the final #. In Rust 2024, the whole sequence is considered a single token.

This lint suggests to add whitespace between the leading # and the string to keep them separated in Rust 2024.