How to embed a Rust macro variable into documentation?

Question

I\'d like to use a macro variable in the macro-generated documentation:

macro_rules! impl_foo {
    ($name:ident) => {
        /// Returns a new `$name`.
         


        

Answer 1

This can be done using a recursive macro:

macro_rules! impl_foo {
    ($name:ident, $sname:expr) => {
        #[doc = "Returns a new `"]
        #[doc = $sname]
        #[doc = "`."]
        pub fn myfoo() -> $name {
            42
        }
    };

    ($name:tt) => {
        impl_foo!($name, stringify!($name));
    };
}

impl_foo!(u32);


fn main() {
    println!("Hello, world!");
}

Which renders as: