Context

Odin:    dev-2025-11-nightly:e5153a9
OS:      macOS Sequoia 15.7.1 (build 24G231, kernel 24.6.0)
CPU:     Apple M3 Pro
RAM:     36864 MiB
Backend: LLVM 20.1.8

Expected Behavior

Using the #optional_ok directive should work as long as the last returned value is a boolean.

Current Behavior

The compiler emits the following error with procedures emitting more two return values:

Error: A procedure type with the #optional_ok tag requires 2 return values, got 3
        foo :: proc(x: int) -> (a, b: int, ok: bool) #optional_ok {
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^

Failure Information

In the Overview documentation, the #optional_ok directive is defined with:

Allows skipping the last return parameter, which needs to be a bool

This implies that number of return values should not matter, as long as last one is a boolean.

I am unable to find other documentation that defines the directive to apply when exactly two values are returned.

Steps to Reproduce

Attempt to compile a modified version of the #optional_ok directive's example on the Overview:

package example

import "core:fmt"

foo :: proc(x: int) -> (a, b: int, ok: bool) #optional_ok {
    return x + 1, x + 2, true
}

main :: proc() {
    ok: bool
    x, y: int
    for i in 0..<11 {
        x, y, ok = foo(i)
        fmt.printf("v: %v %v (%v)\n", x, y, ok)
    }
}

If the #optional_ok directive is removed, the program compiles and runs.