Protocol requirements

A type X meets the Protocol requirements if it satisfies the requirements of Destructible (C++Std [destructible]), CopyConstructible (C++Std [copyconstructible]), and CopyAssignable (C++Std [copyassignable]), as well as the additional requirements listed below.

Table 22. Protocol requirements

expression	return type	assertion/note pre/post-conditions
`X::endpoint`	type meeting endpoint requirements

In the table below, a denotes a (possibly const) value of type X.

Table 23. Protocol requirements for extensible implementations

expression	return type	assertion/note pre/post-conditions
`a.family()`	`int`	Returns a value suitable for passing as the domain argument to POSIX `socket()` (or equivalent).
`a.type()`	`int`	Returns a value suitable for passing as the type argument to POSIX `socket()` (or equivalent).
`a.protocol()`	`int`	Returns a value suitable for passing as the protocol argument to POSIX `socket()` (or equivalent).