Type parameter confusingly inferred to bogus type

[brson]

I wrote the equivalent of this earlier and it baffled me for several minutes.

fn size_of<T>() -> uint {
    // Expecting (though unreasonably) the type parameter to be
    // inferred to T, it is actually inferred to something byte-sized (nil?)
    sys::size_of()
}

fn main() {
    // Why does size_of::<u32>() return 1?
    assert size_of::<u32>() == 4u;
}

It works correctly when you write sys::size_of::<T>(). I don't think this should typecheck.

[marijnh]

I think this is related to a change @nikomatsakis made, where unrestricted type variables, rather than raising an error, are silently converted to _|_. I've had similar problems with it, where I got strange errors when casting things to iface types. I think we should probably make this an error again.

[nikomatsakis]

That is the problem. I'd be happy to make it an error again. I don't like that change.

[nikomatsakis]

Fixed in 2db4259.