Generic parameters VS less then comparison parsing ambiguity

[matklad]

The following

fn main() {
    let _ = 1 as i32 < 1;
}

produces a parse error, because the parser expects type parameters after i32, like in 1 as i32<T>. Is this intentional? Looks like there are no tests for this behavior:

user@UNIT-326 [07:47:36 PM] [~/projects/rust/src/test] [master *]
-> % grep "as \\w* <" -R .              
./run-pass/type-macros-hlist.rs:                  < Expr ! ( HList ! [ $ ( $ LHS ) * ] ) as Add < Expr ! (
./run-pass/type-macros-hlist.rs:                  < Expr ! ( $ LHS ) as Add < Expr ! ( $ ( $ RHS ) + ) >> ::

1 as i32 <= 1 and 1 as i32 > 1 are parsed successfully. 1 as i32 << 1 also fails.
`

[pmarcelll]

It's a known issue: #22644

[nagisa]

What @pmarcelll said.