1 // Copyright (c) 2022 Uber Technologies, Inc.
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining a copy
4 // of this software and associated documentation files (the "Software"), to deal
5 // in the Software without restriction, including without limitation the rights
6 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 // copies of the Software, and to permit persons to whom the Software is
8 // furnished to do so, subject to the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be included in
11 // all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
19 // THE SOFTWARE.
20 21 //go:build go1.19
22 // +build go1.19
23 24 package atomic
25 26 import "sync/atomic"
27 28 // Pointer is an atomic pointer of type *T.
29 type Pointer[T any] struct {
30 _ nocmp // disallow non-atomic comparison
31 p atomic.Pointer[T]
32 }
33 34 // NewPointer creates a new Pointer.
35 func NewPointer[T any](v *T) *Pointer[T] {
36 var p Pointer[T]
37 if v != nil {
38 p.p.Store(v)
39 }
40 return &p
41 }
42 43 // Load atomically loads the wrapped value.
44 func (p *Pointer[T]) Load() *T {
45 return p.p.Load()
46 }
47 48 // Store atomically stores the passed value.
49 func (p *Pointer[T]) Store(val *T) {
50 p.p.Store(val)
51 }
52 53 // Swap atomically swaps the wrapped pointer and returns the old value.
54 func (p *Pointer[T]) Swap(val *T) (old *T) {
55 return p.p.Swap(val)
56 }
57 58 // CompareAndSwap is an atomic compare-and-swap.
59 func (p *Pointer[T]) CompareAndSwap(old, new *T) (swapped bool) {
60 return p.p.CompareAndSwap(old, new)
61 }
62