Cannot assign typeid literals to variables of type Maybe(typeid)

[tadeohepperle]

Context

        Odin:    dev-2025-02:22ab8935c
        OS:      Manjaro Linux, Linux 6.1.126-1-MANJARO
        CPU:     12th Gen Intel(R) Core(TM) i7-1260P
        RAM:     31806 MiB
        Backend: LLVM 14.0.6

Current Behavior

This should work, but does not compile:

a: typeid
a = int // ok
b: Maybe(typeid)
b = int // compile error: `Cannot assign 'int', a type, to assignment`
b = Maybe(typeid)(int) // compile error: `Cannot assign 'int', a type, to assignment`

Steps to Reproduce

main :: proc() {
// for `string` type all is good
	{
		a: string
		a = "Hello" // ok
		b: Maybe(string)
		b = "Hello" // ok
		b = Maybe(string)("Hello") // ok
	}
// for `typeid` type it does not compile:
	{
		a: typeid
		a = int // ok
		b: Maybe(typeid)
		b = int // compile error: `Cannot assign 'int', a type, to assignment`
		b = Maybe(typeid)(int) // compile error: `Cannot assign 'int', a type, to assignment`
	}
}

[Kelimion]

Looks like a type inference thing.
You can get it to work like this:

b: Maybe(typeid)
b = typeid_of(int)
fmt.println("b:", b)

[tadeohepperle]

Great, thanks a lot for your response! :)

[Kelimion]

With that said, you probably don't need Maybe(typeid).

a: typeid
fmt.println(a == nil) // true

If you don't assign anything to the typeid, it has the value nil, but nil itself isn't a type. Maybe is useful to determine whether something was assigned to it, but for a typeid nil already serves that same function.

[laytan]

I believe this is correct, typeid_of is intended to be used to go from a type (not a value) to a typeid (a value).