Enum Occurrences 

pub enum Occurrences {
    Zero,
    Once,
    Many,
}

How often a name occurs — the only distinction an occurrence-gated ζ rule needs.

Variants

Zero

The name does not occur free at all.

Once

Exactly one free occurrence — substituting cannot duplicate anything.

Many

Two or more free occurrences — substituting COPIES the value at each one.

Trait Implementations

impl Clone for Occurrences

fn clone(&self) -> Occurrences

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Occurrences

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Occurrences

fn eq(&self, other: &Occurrences) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Occurrences

impl Eq for Occurrences

impl StructuralPartialEq for Occurrences