spec: Promoted type T gives access to *T receiver.

[egor7]

Hi,
I've faced the following misunderstanding. The ref/spec says that:

Given a struct type S and a type named T, promoted methods are included in the method set of the struct as follows:

• If S contains an anonymous field T, the method sets of S and *S both include promoted methods with receiver T. The method set of *S also includes promoted methods with receiver *T.

So I expect to get an error accessing promoted method of S with anonymouse field T with the receiver *T: see playground
But it compiles well and gives the correct answer instead of an error.

[rjeczalik]

@egor7 Works as expected, the example calls (*S).Val() and not (S).Val(), since it's not l-value. The lack of promotion you can observe with:

https://play.golang.org/p/miJ8-tJWzn

[dominikh]

That isn't caused by S's method set (c.f. https://play.golang.org/p/HdLASR62Js), but by syntactic sugar:

If x is addressable and &x's method set contains m, x.m() is shorthand for (&x).m()

https://golang.org/ref/spec#Calls

(c.f. https://play.golang.org/p/gxZ8nKOeC-)

[egor7]

Thanks.