Why in Go HTTP handlers is ResponseWriter a value and request a pointer?

Question

go

why is the Request object a pointer and ResponseWriter not a pointer? Is there a need for this or is it just to make some advanced pointer based code possible?

Answer 1

ResponseWriter is an interface.
Thus, the argument is the implementation of this interface (instance), which is still passed by pointer.

Answer 2

ResponseWriter is an interface . It is not customary to pass an interface type to a function by reference UsePointer(* SomeInterface ) because such an argument is hard to construct. Even if your MyResponseWriter type satisfies the ResponseWriter interface, you would have to

MyOwnWriter := ResponseWriter(MyResponseWriter)
MyArgument := &MyOwnWriter
//и только потом
UsePointer(MyArgument)