1/* 2Copyright 2018 The Kubernetes Authors. 3 4Licensed under the Apache License, Version 2.0 (the "License"); 5you may not use this file except in compliance with the License. 6You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10Unless required by applicable law or agreed to in writing, software 11distributed under the License is distributed on an "AS IS" BASIS, 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13See the License for the specific language governing permissions and 14limitations under the License. 15*/ 16 17package pointer 18 19import ( 20 "fmt" 21 "reflect" 22) 23 24// AllPtrFieldsNil tests whether all pointer fields in a struct are nil. This is useful when, 25// for example, an API struct is handled by plugins which need to distinguish 26// "no plugin accepted this spec" from "this spec is empty". 27// 28// This function is only valid for structs and pointers to structs. Any other 29// type will cause a panic. Passing a typed nil pointer will return true. 30func AllPtrFieldsNil(obj interface{}) bool { 31 v := reflect.ValueOf(obj) 32 if !v.IsValid() { 33 panic(fmt.Sprintf("reflect.ValueOf() produced a non-valid Value for %#v", obj)) 34 } 35 if v.Kind() == reflect.Ptr { 36 if v.IsNil() { 37 return true 38 } 39 v = v.Elem() 40 } 41 for i := 0; i < v.NumField(); i++ { 42 if v.Field(i).Kind() == reflect.Ptr && !v.Field(i).IsNil() { 43 return false 44 } 45 } 46 return true 47} 48 49// Int32Ptr returns a pointer to an int32 50func Int32Ptr(i int32) *int32 { 51 return &i 52} 53 54// Int32PtrDerefOr dereference the int32 ptr and returns it if not nil, 55// else returns def. 56func Int32PtrDerefOr(ptr *int32, def int32) int32 { 57 if ptr != nil { 58 return *ptr 59 } 60 return def 61} 62 63// Int64Ptr returns a pointer to an int64 64func Int64Ptr(i int64) *int64 { 65 return &i 66} 67 68// Int64PtrDerefOr dereference the int64 ptr and returns it if not nil, 69// else returns def. 70func Int64PtrDerefOr(ptr *int64, def int64) int64 { 71 if ptr != nil { 72 return *ptr 73 } 74 return def 75} 76 77// BoolPtr returns a pointer to a bool 78func BoolPtr(b bool) *bool { 79 return &b 80} 81 82// BoolPtrDerefOr dereference the bool ptr and returns it if not nil, 83// else returns def. 84func BoolPtrDerefOr(ptr *bool, def bool) bool { 85 if ptr != nil { 86 return *ptr 87 } 88 return def 89} 90 91// StringPtr returns a pointer to the passed string. 92func StringPtr(s string) *string { 93 return &s 94} 95 96// StringPtrDerefOr dereference the string ptr and returns it if not nil, 97// else returns def. 98func StringPtrDerefOr(ptr *string, def string) string { 99 if ptr != nil { 100 return *ptr 101 } 102 return def 103} 104 105// Float32Ptr returns a pointer to the passed float32. 106func Float32Ptr(i float32) *float32 { 107 return &i 108} 109 110// Float32PtrDerefOr dereference the float32 ptr and returns it if not nil, 111// else returns def. 112func Float32PtrDerefOr(ptr *float32, def float32) float32 { 113 if ptr != nil { 114 return *ptr 115 } 116 return def 117} 118 119// Float64Ptr returns a pointer to the passed float64. 120func Float64Ptr(i float64) *float64 { 121 return &i 122} 123 124// Float64PtrDerefOr dereference the float64 ptr and returns it if not nil, 125// else returns def. 126func Float64PtrDerefOr(ptr *float64, def float64) float64 { 127 if ptr != nil { 128 return *ptr 129 } 130 return def 131} 132