Pragya Arya | 324337e | 2020-02-20 14:35:08 +0530 | [diff] [blame] | 1 | // Copyright 2018, The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
David K. Bainbridge | c415efe | 2021-08-19 13:05:21 +0000 | [diff] [blame^] | 3 | // license that can be found in the LICENSE file. |
Pragya Arya | 324337e | 2020-02-20 14:35:08 +0530 | [diff] [blame] | 4 | |
| 5 | // +build !purego |
| 6 | |
| 7 | package value |
| 8 | |
| 9 | import ( |
| 10 | "reflect" |
| 11 | "unsafe" |
| 12 | ) |
| 13 | |
| 14 | // Pointer is an opaque typed pointer and is guaranteed to be comparable. |
| 15 | type Pointer struct { |
| 16 | p unsafe.Pointer |
| 17 | t reflect.Type |
| 18 | } |
| 19 | |
| 20 | // PointerOf returns a Pointer from v, which must be a |
| 21 | // reflect.Ptr, reflect.Slice, or reflect.Map. |
| 22 | func PointerOf(v reflect.Value) Pointer { |
| 23 | // The proper representation of a pointer is unsafe.Pointer, |
| 24 | // which is necessary if the GC ever uses a moving collector. |
| 25 | return Pointer{unsafe.Pointer(v.Pointer()), v.Type()} |
| 26 | } |
David K. Bainbridge | c415efe | 2021-08-19 13:05:21 +0000 | [diff] [blame^] | 27 | |
| 28 | // IsNil reports whether the pointer is nil. |
| 29 | func (p Pointer) IsNil() bool { |
| 30 | return p.p == nil |
| 31 | } |
| 32 | |
| 33 | // Uintptr returns the pointer as a uintptr. |
| 34 | func (p Pointer) Uintptr() uintptr { |
| 35 | return uintptr(p.p) |
| 36 | } |