| /* |
| Copyright 2018 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 pointer |
| |
| import ( |
| "fmt" |
| "reflect" |
| ) |
| |
| // AllPtrFieldsNil tests whether all pointer fields in a struct are nil. This is useful when, |
| // for example, an API struct is handled by plugins which need to distinguish |
| // "no plugin accepted this spec" from "this spec is empty". |
| // |
| // This function is only valid for structs and pointers to structs. Any other |
| // type will cause a panic. Passing a typed nil pointer will return true. |
| func AllPtrFieldsNil(obj interface{}) bool { |
| v := reflect.ValueOf(obj) |
| if !v.IsValid() { |
| panic(fmt.Sprintf("reflect.ValueOf() produced a non-valid Value for %#v", obj)) |
| } |
| if v.Kind() == reflect.Ptr { |
| if v.IsNil() { |
| return true |
| } |
| v = v.Elem() |
| } |
| for i := 0; i < v.NumField(); i++ { |
| if v.Field(i).Kind() == reflect.Ptr && !v.Field(i).IsNil() { |
| return false |
| } |
| } |
| return true |
| } |
| |
| // Int32Ptr returns a pointer to an int32 |
| func Int32Ptr(i int32) *int32 { |
| return &i |
| } |
| |
| // Int64Ptr returns a pointer to an int64 |
| func Int64Ptr(i int64) *int64 { |
| return &i |
| } |
| |
| // Int32PtrDerefOr dereference the int32 ptr and returns it i not nil, |
| // else returns def. |
| func Int32PtrDerefOr(ptr *int32, def int32) int32 { |
| if ptr != nil { |
| return *ptr |
| } |
| return def |
| } |
| |
| // BoolPtr returns a pointer to a bool |
| func BoolPtr(b bool) *bool { |
| return &b |
| } |
| |
| // StringPtr returns a pointer to the passed string. |
| func StringPtr(s string) *string { |
| return &s |
| } |
| |
| // Float32Ptr returns a pointer to the passed float32. |
| func Float32Ptr(i float32) *float32 { |
| return &i |
| } |
| |
| // Float64Ptr returns a pointer to the passed float64. |
| func Float64Ptr(i float64) *float64 { |
| return &i |
| } |