Scalar Value Types Problems repeated string --> why not []*string pass by reference

[shiywang]

according to scalar value types in golang

.proto Type                Golang Type
string               -->      *string

But why repeated string --> []string instead of repeated string --> []*string ?

My user case is here:
I'm using reflect to set value to Message struct, roughly like this:

v := reflect.ValueOf(msg).Elem()
switch v.Field(i).Interface().(type) {
         case *bool:
                      var tmpBool bool
                      cmd.Flags().BoolVarP(&tmpBool, name, shorthand, bVal, usage) 
		      v.Field(i).Set(reflect.ValueOf(&tmpBool))
         case []string:
                      var tmpSliceString []string
		      cmd.Flags().StringSliceVarP(&tmpSliceString, name, shorthand, defaultValue, usage)
                      v.Field(i).Set(reflect.ValueOf(tmpSliceString))   //set the SliceFlag here
...


My message struct is below:
type Test struct {
	BoolFlag         *bool    `protobuf:"varint,1,opt,name=BoolFlag" json:"BoolFlag,omitempty"`
	StringFlag       *string  `protobuf:"bytes,2,opt,name=StringFlag" json:"StringFlag,omitempty"`
	Int32Flag        *int32   `protobuf:"varint,3,opt,name=Int32Flag" json:"Int32Flag,omitempty"`
	SliceFlag        []string `protobuf:"bytes,4,rep,name=SliceFlag" json:"SliceFlag,omitempty"`
	XXX_unrecognized []byte   `json:"-"`
}

the value tmpBool is currently only initial but it may be changed in other places, so pass a *bool can make my message perceive the changes, but []string without pointer only copy the value which initial just empty, but that value may changed, but message can't perceive that.

is there any way to generate []*string maybe ? if not, is there any workaround here?
Thanks

[shiywang]

I've find a workaround here using an extra message which can pass by reference instead of value

message Slice {
    repeated string value = 1;
}

case *cmdproto.Slice:
	switch ext {
	case cmdproto.FlagDetail_ISSTRSLICE:
		var tmpSliceString cmdproto.Slice
		cmd.Flags().StringSliceVarP(&tmpSliceString.Value, name, shorthand, defaultValue, usage)
		v.Field(i).Set(reflect.ValueOf(&tmpSliceString))

but still wondering why not repeated string --> []*string

[dsnet]

The proto2 format allows for optional values. Since Go lacks optional types or unions types, it resorted to using pointers to indicate the difference between a set zero value and an unset value. As for slices, there is no need to make that distinction.

Furthermore, I don't think it's feasible to add an option just to allow generating []*string instead of []string.