error: expected identifier, found keyword `true`
  --> $DIR/issue-44406.rs:8:10
   |
LL |     foo!(true);
   |          ^^^^ expected identifier, found keyword
   |
help: you can escape reserved keywords to use them as identifiers
   |
LL |     foo!(r#true);
   |          ^^^^^^

error: expected type, found keyword `true`
  --> $DIR/issue-44406.rs:8:10
   |
LL |         bar(baz: $rest)
   |                - help: try using a semicolon: `;`
...
LL |     foo!(true);
   |          ^^^^ expected type
   |
   = note: `#![feature(type_ascription)]` lets you annotate an expression with a type: `<expr>: <type>`
   = note: for more information, see https://github.com/rust-lang/rust/issues/23416

error: aborting due to 2 previous errors