Both arguments must have <a href="#Type_identity">identical</a> element type <code>T</code> and must be
<a href="#Assignability">assignable</a> to a slice of type <code>[]T</code>.
The number of elements copied is the minimum of
<code>len(src)</code> and <code>len(dst)</code>.
As a special case, <code>copy</code> also accepts a destination argument assignable
to type <code>[]byte</code> with a source argument of a string type.

allows individual programs to opt back in to the old behavior.
A GODEBUG setting may not be added if doing so is infeasible,
but that should be extremely rare.

GODEBUG settings added for compatibility will be maintained
for a minimum of two years (four Go releases).
Some, such as `http2client` and `http2server`,
will be maintained much longer, even indefinitely.

When possible, each GODEBUG setting has an associated

then an `api/next` file with the line

    pkg net/http, function F #12345

should have a corresponding file named `doc/next/6-stdlib/99-minor/net/http/12345.md`.
At a minimum, that file should contain either a full sentence or a TODO,
ideally referring to a person with the responsibility to complete the note.

Use the following forms in your markdown:

// destination slice. (As a special case, it also will copy bytes from a
// string to a slice of bytes.) The source and destination may overlap. Copy
// returns the number of elements copied, which will be the minimum of
// len(src) and len(dst).
func copy(dst, src []Type) int

// The delete built-in function deletes the element with the specified key
// (m[key]) from the map. If m is nil or there is no such element, delete

language.
</p>

<p>
A link of the form [<a href="#Language_versions">Go 1.xx</a>] indicates that a described
language feature (or some aspect of it) was changed or added with language version 1.xx and
thus requires at minimum that language version to build.
For details, see the <a href="#Language_versions">linked section</a>
in the <a href="#Appendix">appendix</a>.
</p>

<h2 id="Source_code_representation">Source code representation</h2>