1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE-go file.
package deepequal
import "unsafe"
type value struct {
// typ holds the type of the value represented by a Value.
typ *rtype
// Pointer-valued data or, if flagIndir is set, pointer to data.
// Valid when either flagIndir is set or typ.pointers() is true.
ptr unsafe.Pointer
// flag holds metadata about the value.
// The lowest bits are flag bits:
// - flagStickyRO: obtained via unexported not embedded field, so read-only
// - flagEmbedRO: obtained via unexported embedded field, so read-only
// - flagIndir: val holds a pointer to the data
// - flagAddr: v.CanAddr is true (implies flagIndir)
// - flagMethod: v is a method value.
// The next five bits give the Kind of the value.
// This repeats typ.Kind() except for method values.
// The remaining 23+ bits give a method number for method values.
// If flag.kind() != Func, code can assume that flagMethod is unset.
// If ifaceIndir(typ), code can assume that flagIndir is set.
flag
// A method value represents a curried method invocation
// like r.Read for some receiver r. The typ+val+flag bits describe
// the receiver r, but the flag's Kind bits say Func (methods are
// functions), and the top bits of the flag give the method number
// in r's type's method table.
}
type flag uintptr
const (
flagKindWidth = 5 // there are 27 kinds
flagKindMask flag = 1<<flagKindWidth - 1
flagStickyRO flag = 1 << 5
flagEmbedRO flag = 1 << 6
flagIndir flag = 1 << 7
flagAddr flag = 1 << 8
flagMethod flag = 1 << 9
flagMethodShift = 10
flagRO flag = flagStickyRO | flagEmbedRO
)
|
