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authorTianon Gravi <admwiggin@gmail.com>2015-01-15 11:54:00 -0700
committerTianon Gravi <admwiggin@gmail.com>2015-01-15 11:54:00 -0700
commitf154da9e12608589e8d5f0508f908a0c3e88a1bb (patch)
treef8255d51e10c6f1e0ed69702200b966c9556a431 /src/unsafe/unsafe.go
parent8d8329ed5dfb9622c82a9fbec6fd99a580f9c9f6 (diff)
downloadgolang-f154da9e12608589e8d5f0508f908a0c3e88a1bb.tar.gz
Imported Upstream version 1.4upstream/1.4
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+// 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.
+
+/*
+ Package unsafe contains operations that step around the type safety of Go programs.
+
+ Packages that import unsafe may be non-portable and are not protected by the
+ Go 1 compatibility guidelines.
+*/
+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 four 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 Pointer can be converted to a pointer value of any type.
+// 3) A uintptr can be converted to a Pointer.
+// 4) 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) uintptr
+
+// Offsetof returns the offset within the struct of the field represented by v,
+// which must be of the form structValue.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) uintptr
+
+// Alignof returns the alignment of the value v. It is the maximum value m such
+// that the address of a variable with the type of v will always be zero mod m.
+// If v is of the form structValue.field, it returns the alignment of field f within struct object obj.
+func Alignof(v ArbitraryType) uintptr