I wish to model a value which can have two possible forms: absent, or a string.
The natural way to do this is with Maybe String
, or Optional<String>
, or string option
, etc. However, Go does not have variant types like this.
I then thought, following Java, C, etc., that the alternative would be nullability, or nil
in Go. However, nil
is not a member of the string
type in Go.
Searching, I then thought to use the type *string
. This could work, but seems very awkward (e.g. I cannot take the address of the string literal in the same way that I can take the address of a struct literal).
What is the idiomatic way to model such a value in Go?
You could use something like
sql.NullString
, but I personally would stick to*string
. As for awkwardness, it's true that you can't justsp := &"foo"
unfortunately. But there is a workaround for this:Calls to
strPtr("foo")
should be inlined, so it's effectively&"foo"
.Another possibility is to use
new
: