named_return 0.1.1

Derives a wrapper function which insert the named return variables.

Named Return

Declares a proc-macro that enables return types to be named.
Mostly re-defining structures from syn for parsing.

The macro also:

  1. Declares the variables that were named as a prefix statement to the original function's body.
  2. Requires that the return syntax is similar to the input parameter syntax.
    • Requires parentheses.


use named_return::named_return;
# #[derive(Debug, PartialEq, Eq)]
# pub struct A;
# #[derive(Debug, PartialEq, Eq)]
# pub struct B;

fn f() -> (a: A, b: B) {
    a = A;
    b = B;
    (a, b)

assert_eq!(f(), (A, B));


The intended syntax were to be used with a proc-macro-attr, such as:

fn f() -> (a: A, b: B) {
    a = A;
    b = B;
    (a, b)

But it seems that Rust parses the original function syntax before executing the proc-macro-attr and so it refuses the invalid syntax.

This is a draft and is based on this suggestion: