Creating Slice from Reflected Type

Question

I am trying to create a slice from a reflect.Type. This is what I have so far.

package main

import (
    "fmt"
    "reflect"
)

type TestStruct struct {
    TestStr string
}

func main() {
    elemType := reflect.TypeOf(TestStruct{})

    elemSlice := reflect.New(reflect.SliceOf(elemType)).Interface()

    elemSlice = append(elemSlice, TestStruct{"Testing"})

    fmt.Printf("%+v\n", elemSlice)

}

However I get the following error and I'm not sure how to get around it without hardcoding a conversion to []TestStruct.

prog.go:17: first argument to append must be slice; have interface {}

Is there anyway to treat the returned interface as a slice without having to hardcode the conversion from interface{} to []TestStruct?

Answer 1

No, what you describe is not possible. Not type asserting the result of .Interface() limits what you can do. Your best chance is to continue to work with the reflect.Value value:

package main

import (
    "fmt"
    "reflect"
)

type TestStruct struct {
    TestStr string
}

func main() {
    elemType := reflect.TypeOf(TestStruct{})

    elemSlice := reflect.MakeSlice(reflect.SliceOf(elemType), 0, 10)

    elemSlice = reflect.Append(elemSlice, reflect.ValueOf(TestStruct{"Testing"}))

    fmt.Printf("%+v\n", elemSlice)

}

https://play.golang.org/p/WkGPjv0m_P