Be careful with Go struct embedding

Go has a feature called struct embedding that allows you to compose types. It looks something like this: type Position struct { X int Y int } type Colour struct { R byte G byte B byte } type Rectangle struct { Position Colour Width int Height int } r := Rectangle { } fmt . Printf ( "%d,%d " , r . Position . X , r . Position . Y ) fmt . Printf ( "%d,%d " , r . X , r . Y ) But what do you think this code does? type FooService struct { URL string } type BarConnectionOptions struct { URL string } type BarService struct { BarConnectionOptions } type Options struct { FooService BarService } opts := Options { FooService : FooService { URL : "abc.com" }, BarService : BarService { BarConnectionOptions : BarConnectionOptions { URL : "xyz.com" , }, }, } fmt . Println ( opts . URL )