Struct Invalid 

pub struct Invalid;

A unit that always fails to match. This is useful as default for generics. See how Either<A, B, C, D> uses this for unused alternatives.

Trait Implementations

impl Clone for Invalid

fn clone(&self) -> Invalid

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Invalid

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

Formats the value using the given formatter.

impl Parser for Invalid

fn parser( tokens: &mut ShadowCountedIter<'_, <TokenStream as IntoIterator>::IntoIter>, ) -> Result<Invalid, Error>

The actual parsing function that must be implemented. This mutates the tokens iterator directly. It should not be called from user code except for implementing parsers itself and then only when the rules below are followed.

impl ToTokens for Invalid

fn to_tokens(&self, _tokens: &mut TokenStream)

Write &self to the given TokenStream.

fn to_token_iter( &self, ) -> ShadowCountedIter<'_, <TokenStream as IntoIterator>::IntoIter>

Convert &self into a TokenIter object.

fn into_token_iter<'a>( self, ) -> ShadowCountedIter<'a, <TokenStream as IntoIterator>::IntoIter>

where Self: Sized,

Convert self into a TokenIter object.

fn to_token_stream(&self) -> TokenStream

Convert &self into a TokenStream object.

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Convert self into a TokenStream object.

fn tokens_to_string(&self) -> String

Convert &self into a String object. This is mostly used in the test suite to compare the outputs. When the input is a &str then this parses it and returns a normalized String.