pub struct Invalid;Expand description
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.
§Panics
Invalid tokens can not be emitted and will panic when calling ToTokens::to_tokens().
Trait Implementations§
Source§impl ToTokens for Invalid
impl ToTokens for Invalid
Source§fn to_tokens(&self, _tokens: &mut TokenStream)
fn to_tokens(&self, _tokens: &mut TokenStream)
Source§fn into_token_iter(self) -> TokenIter ⓘwhere
Self: Sized,
fn into_token_iter(self) -> TokenIter ⓘwhere
Self: Sized,
Convert
self into a TokenIter object.Source§fn to_token_stream(&self) -> TokenStream
fn to_token_stream(&self) -> TokenStream
Convert
&self into a TokenStream object.Source§fn into_token_stream(self) -> TokenStreamwhere
Self: Sized,
fn into_token_stream(self) -> TokenStreamwhere
Self: Sized,
Convert
self into a TokenStream object.Auto Trait Implementations§
impl Freeze for Invalid
impl RefUnwindSafe for Invalid
impl Send for Invalid
impl Sync for Invalid
impl Unpin for Invalid
impl UnwindSafe for Invalid
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§impl<T> DynamicTokens for T
impl<T> DynamicTokens for T
Source§impl<T> Parse for Twhere
T: Parser,
impl<T> Parse for Twhere
T: Parser,
Source§fn parse(tokens: &mut TokenIter) -> Result<Self, Error>
fn parse(tokens: &mut TokenIter) -> Result<Self, Error>
This is the user facing API to parse grammatical entities. Calls a
parser() within a
transaction. Commits changes on success and returns the parsed value. Read more