n2 := copy(s, s[2:])            // n2 == 4, s == []int{2, 3, 4, 5, 4, 5}
n3 := copy(b, "Hello, World!")  // n3 == 5, b == []byte("Hello")
</pre>


<h3 id="Deletion_of_map_elements">Deletion of map elements</h3>

<p>
The built-in function <code>delete</code> removes the element with key
<code>k</code> from a <a href="#Map_types">map</a> <code>m</code>. The

pkg go/types, method (*Selection) Index() []int
pkg go/types, method (*Selection) Indirect() bool
pkg go/types, method (*Selection) Kind() SelectionKind
pkg go/types, method (*Selection) Obj() Object
pkg go/types, method (*Selection) Recv() Type
pkg go/types, method (*Selection) String() string
pkg go/types, method (*Selection) Type() Type
pkg go/types, method (*Signature) Params() *Tuple

			if !ok {
				continue
			}
			for _, spec := range d.Specs {
				if s, ok := spec.(*ast.ImportSpec); ok && s.Path.Value == `"C"` {
					// Replace "C" with _ "unsafe", to keep program valid.
					// (Deleting import statement or clause is not safe if it is followed
					// in the source by an explicit semicolon.)
					f.Edit.Replace(f.offset(s.Path.Pos()), f.offset(s.Path.End()), `_ "unsafe"`)
				}
			}
		}
	}

		File: []ZipTestFile{
			{
				Name:    "世界",
				Content: []byte{},
				Mode:    0644,
				// Name is valid UTF-8, but format does not have UTF-8 flag set.
				// We don't do UTF-8 detection for multi-byte runes due to
				// false-positives with other encodings (e.g., Shift-JIS).
				// Format says encoding is not UTF-8, so we trust it.
				NonUTF8:  true,

a "vendor/" prefix also maintains the invariant that standard
library packages begin with a dotless path element.

The module requirements of std and cmd do not influence version
selection in other modules. They are only considered when running
module commands like 'go get' and 'go mod vendor' from a directory
in GOROOT/src.

Maintaining vendor directories
==============================

		//	----------  0 0      0           0 May 13  2014 file4
		//
		// GNU tar v1.27.1 applies global headers to subsequent records,
		// but does not do the following properly:
		//	* It does not treat an empty record as deletion.
		//	* It does not use subsequent global headers to update previous ones.
		//
		//	$ gnutar -tvf pax-global-records.tar
		//	---------- 0/0               0 2017-07-13 19:40 global1

pkg syscall (linux-386), const RTF_WINDOW ideal-int
pkg syscall (linux-386), const RTF_XRESOLVE ideal-int
pkg syscall (linux-386), const RTM_BASE ideal-int
pkg syscall (linux-386), const RTM_DELACTION ideal-int
pkg syscall (linux-386), const RTM_DELADDR ideal-int
pkg syscall (linux-386), const RTM_DELADDRLABEL ideal-int
pkg syscall (linux-386), const RTM_DELLINK ideal-int

_ = imag(3 << s)                   // illegal: 3 assumes complex type, cannot shift
</pre>

<p>
Arguments of type parameter type are not permitted.
</p>


<h3 id="Deletion_of_map_elements">Deletion of map elements</h3>

<p>
The built-in function <code>delete</code> removes the element with key
<code>k</code> from a <a href="#Map_types">map</a> <code>m</code>. The

</p>

<p>
The <i>synchronized before</i> relation is a partial order on synchronizing memory operations,
derived from <i>W</i>.
If a synchronizing read-like memory operation <i>r</i>
observes a synchronizing write-like memory operation <i>w</i>
(that is, if <i>W</i>(<i>r</i>) = <i>w</i>),
then <i>w</i> is synchronized before <i>r</i>.
Informally, the synchronized before relation is a subset of the implied total order

		var prefix string
		switch {
		case format.has(FormatUSTAR | FormatPAX):
			hdr.Format = format
			ustar := tr.blk.toUSTAR()
			prefix = p.parseString(ustar.prefix())

			// For Format detection, check if block is properly formatted since
			// the parser is more liberal than what USTAR actually permits.
			notASCII := func(r rune) bool { return r >= 0x80 }
			if bytes.IndexFunc(tr.blk[:], notASCII) >= 0 {