Struct Protocol 

pub struct Protocol { /* private fields */ }

A Swift protocol descriptor, read only as far as this needs.

Implementations

impl Protocol

pub unsafe fn from_symbol(symbol: &'static CStr) -> Self

Read the descriptor symbol names.

Safety

symbol must be a protocol descriptor (...Mp).

pub fn requirement_count(&self) -> usize

How many requirements the protocol has, and so how wide a witness table for it must be.

pub fn describe(&self)

Print each requirement’s kind and whether it has a default.

Only for working out what a protocol needs; nothing depends on it.

pub fn has_default(&self, i: usize) -> bool

The default implementation of requirement i, if it has one. Whether requirement i has a default, and so need not be supplied.

The ratio of defaults to requirements is what decides whether a conformance is worth synthesising: View has one requirement and several defaults, Layout has many of each.