/*
Implementation details.

Cgo provides a way for Go programs to call C code linked into the same
address space. This comment explains the operation of cgo.

Cgo reads a set of Go source files and looks for statements saying
import "C". If the import has a doc comment, that comment is
taken as literal C code to be used as a preamble to any C code
generated by cgo. A typical preamble #includes necessary definitions:

	// #include <stdio.h>

sent values have been received, receive operations will return
the zero value for the channel's type without blocking.
The multi-valued <a href="#Receive_operator">receive operation</a>
returns a received value along with an indication of whether the channel is closed.
</p>


<h3 id="Length_and_capacity">Length and capacity</h3>

<p>
The built-in functions <code>len</code> and <code>cap</code> take arguments

This setting will be removed in a future release, Go 1.22 at the earliest.

### Go 1.10

Go 1.10 changed how build caching worked and added test caching, along
with the [`gocacheverify`, `gocachehash`, and `gocachetest` settings](/cmd/go/#hdr-Build_and_test_caching).
There is no plan to remove these settings.

### Go 1.6

Go 1.6 introduced transparent support for HTTP/2,

sent values have been received, receive operations will return
the zero value for the channel's type without blocking.
The multi-valued <a href="#Receive_operator">receive operation</a>
returns a received value along with an indication of whether the channel is closed.
</p>


<h3 id="Complex_numbers">Manipulating complex numbers</h3>

<p>
Three functions assemble and disassemble complex numbers.