diff options
author | Rob Pike <r@golang.org> | 2009-06-09 09:53:44 -0700 |
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committer | Rob Pike <r@golang.org> | 2009-06-09 09:53:44 -0700 |
commit | 7249ea4df2b4f12a4e7ed446f270cea87e4ffd34 (patch) | |
tree | 7032a11d0cac2ae4d3e90f7a189b575b5a50f848 /src/pkg/unsafe | |
parent | acf6ef7a82b3fe61516a1bac4563706552bdf078 (diff) | |
download | golang-7249ea4df2b4f12a4e7ed446f270cea87e4ffd34.tar.gz |
mv src/lib to src/pkg
tests: all.bash passes, gobuild still works, godoc still works.
R=rsc
OCL=30096
CL=30102
Diffstat (limited to 'src/pkg/unsafe')
-rw-r--r-- | src/pkg/unsafe/unsafe.go | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/pkg/unsafe/unsafe.go b/src/pkg/unsafe/unsafe.go new file mode 100644 index 000000000..b19af405b --- /dev/null +++ b/src/pkg/unsafe/unsafe.go @@ -0,0 +1,44 @@ +// 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 file. + +/* + The unsafe package contains operations that step around the type safety of Go programs. + */ +package unsafe + +// ArbitraryType is here for the purposes of documentation only and is not actually +// part of the unsafe package. It represents the type of an arbitrary Go expression. +type ArbitraryType int + +// Pointer represents a pointer to an arbitrary type. There are three special operations +// available for type Pointer that are not available for other types. +// 1) A pointer value of any type can be converted to a Pointer. +// 2) A uintptr can be converted to a Pointer. +// 3) A Pointer can be converted to a uintptr. +// Pointer therefore allows a program to defeat the type system and read and write +// arbitrary memory. It should be used with extreme care. +type Pointer *ArbitraryType + +// Sizeof returns the size in bytes occupied by the value v. The size is that of the +// "top level" of the value only. For instance, if v is a slice, it returns the size of +// the slice descriptor, not the size of the memory referenced by the slice. +func Sizeof(v ArbitraryType) int + +// Offsetof returns the offset within the struct of the field represented by v, +// which must be of the form struct_value.field. In other words, it returns the +// number of bytes between the start of the struct and the start of the field. +func Offsetof(v ArbitraryType) int + +// Alignof returns the alignment of the value v. It is the minimum value m such +// that the address of a variable with the type of v will always always be zero mod m. +// If v is of the form obj.f, it returns the alignment of field f within struct object obj. +func Alignof(v ArbitraryType) int + +// Reflect unpacks an interface value into its internal value word and its type string. +// The boolean indir is true if the value is a pointer to the real value. +func Reflect(i interface {}) (value uint64, typestring string, indir bool) + +// Unreflect inverts Reflect: Given a value word, a type string, and the indirect bit, +// it returns an empty interface value with those contents. +func Unreflect(value uint64, typestring string, indir bool) (ret interface {}) |