struct initialization

[cunning rock]

Hi this is more syntax related question..

Suppose I have an interface as follows:

type ReaderWriter interface {
Reader, Writer
}

is it possible to init such type using a struct literal only?
e.g.

var rw ReaderWriter
var rd cReader // implements Reader
var wr cWriter // implements Writer

rw = (ReaderWriter)(struct{rd, wr})

[placid zenith]

no, since struct{rd, wr} would not implement ReaderWriter

an anonymous struct can only implement the interface{} interface since anonymous structs cannot have methods

[cunning rock]

yeah is there any other way where I could init such type using a oneliner and without introducing another type that embbeds the Reader and Writer structs?

[placid zenith]

uh

technically you could

here's a hint

    var x io.ReadWriter = struct {
        io.Reader
        io.Writer
    }{}

[placid zenith]

this is wrong, then

[cunning rock]

uhm.. you mean?

    var x io.ReadWriter x := struct {
        cReader
        cWriter
    }{}

[placid zenith]

not that, but i had another mistake

[round mantle]

yes because embedded fields (or promoted methods) are accounted for in interface "satisfaction"

[cunning rock]

yeah it works

[gilded escarp]

you can do:

var rw ReaderWriter = struct{Reader; Writer}{rd, wr}

[placid zenith]

thank you for repeating the answer again