pub(crate) enum MetaVarExpr {
    Count(Ident, Option<usize>),
    Ignore(Ident),
    Index(usize),
    Length(usize),
}
Expand description

A meta-variable expression, for expansions based on properties of meta-variables.

Variants§

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Count(Ident, Option<usize>)

The number of repetitions of an identifier, optionally limited to a number of outer-most repetition depths. If the depth limit is None then the depth is unlimited.

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Ignore(Ident)

Ignore a meta-variable for repetition without expansion.

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Index(usize)

The index of the repetition at a particular depth, where 0 is the inner-most repetition. The usize is the depth.

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Length(usize)

The length of the repetition at a particular depth, where 0 is the inner-most repetition. The usize is the depth.

Implementations§

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impl MetaVarExpr

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pub(crate) fn parse<'sess>( input: &TokenStream, outer_span: Span, sess: &'sess ParseSess ) -> PResult<'sess, MetaVarExpr>

Attempt to parse a meta-variable expression from a token stream.

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pub(crate) fn ident(&self) -> Option<Ident>

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impl Clone for MetaVarExpr

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fn clone(&self) -> MetaVarExpr

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for MetaVarExpr

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

Formats the value using the given formatter. Read more
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impl<__D: Decoder> Decodable<__D> for MetaVarExpr

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fn decode(__decoder: &mut __D) -> Self

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impl<__E: Encoder> Encodable<__E> for MetaVarExpr

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fn encode(&self, __encoder: &mut __E)

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impl PartialEq for MetaVarExpr

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

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl StructuralPartialEq for MetaVarExpr

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 32 bytes

Size for each variant:

  • Count: 32 bytes
  • Ignore: 20 bytes
  • Index: 16 bytes
  • Length: 16 bytes