metrics-server/vendor/k8s.io/apimachinery/pkg/conversion/helper.go

/*
Copyright 2014 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package conversion

import (
	"fmt"
	"reflect"
)

// EnforcePtr ensures that obj is a pointer of some sort. Returns a reflect.Value
// of the dereferenced pointer, ensuring that it is settable/addressable.
// Returns an error if this is not possible.
func EnforcePtr(obj interface{}) (reflect.Value, error) {
	v := reflect.ValueOf(obj)
	if v.Kind() != reflect.Ptr {
		if v.Kind() == reflect.Invalid {
			return reflect.Value{}, fmt.Errorf("expected pointer, but got invalid kind")
		}
		return reflect.Value{}, fmt.Errorf("expected pointer, but got %v type", v.Type())
	}
	if v.IsNil() {
		return reflect.Value{}, fmt.Errorf("expected pointer, but got nil")
	}
	return v.Elem(), nil
}