I don't understand the meaning of the double {}. This is not made clear in any learning material. Thanks.
variable <-struct {}{}
variable is a variable of type channel (values are sent on it)
<- is a send operator
struct{} is type empty struct (has no fields)
{} makes it a struct literal (creates a value of the given struct type)
To better understand this form let me give you an example of a different struct type:
p := struct{ X, Y float64 }{0.0, 0.0}
I don't understand the meaning of the double {}.
struct {}{}
In long form,
type T struct{}
var t = T{}
struct {} is a type, a struct with no fields, and struct {}{} is a composite literal, with zero values, of that type.
References: