* Processing a response after being generated by *path operation functions* but before returning it. E.g. adding custom headers, logging, adding extra metadata.
    * New docs section: [Custom Request and APIRoute class](https://fastapi.tiangolo.com/advanced/custom-request-and-route/).

Tag           = string_lit .
</pre>

<pre>
// An empty struct.
struct {}

// A struct with 6 fields.
struct {
	x, y int
	u float32
	_ float32  // padding
	A *[]int
	F func()
}
</pre>

<p>
A field declared with a type but no explicit field name is called an <i>embedded field</i>.
An embedded field must be specified as