What is `r#variable`?

help
1

I saw r#variable in here. Looks like it's Rust syntax.

  • What does it do?
  • What's the difference from the normal variable?
  • How come r#variable allowed to use (f#variable or other alphabet does not work)?
  • Is it related to r#""# ?

Thanks

2

they are called raw identifiers:

https://doc.rust-lang.org/stable/reference/identifiers.html#raw-identifiers

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3

Got it. I didn't know I can use it for variables as well as string like let r#const = "test";.
do you know what else we can use it for (variables, string text etc)?
Thanks!

4

Everything that used identifiers for a name. Such as the names of variables, function and closure parameters, bindings introduced by match or if let or for, type synonyms, enums, structs, traits, modules; the names of functions, associated items (e. g. associated types), constants (i. e. const items), macros.

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5

r#ident and r#"string"# are different constructs. The former is an identifier and the latter is a string literal. They are designed to look similar to avoid weirdness, but the r# prefix doesn't have to be (and isn't) universally applicable to any other kind of language construct.

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