Enum rustc_builtin_macros::deriving::generic::CsFold

source · [−]
pub enum CsFold<'a> {
    Single(&'a FieldInfo),
    Combine(Span, P<Expr>, P<Expr>),
    Fieldless,
    EnumNonMatching(Span, &'a [Ident]),
}
Expand description

The function passed to cs_fold is called repeatedly with a value of this type. It describes one part of the code generation. The result is always an expression.

Variants

Single(&'a FieldInfo)

The basic case: a field expression for one or more selflike args. E.g. for PartialEq::eq this is something like self.x == other.x.

Combine(Span, P<Expr>, P<Expr>)

The combination of two field expressions. E.g. for PartialEq::eq this is something like <field1 equality> && <field2 equality>.

Fieldless

EnumNonMatching(Span, &'a [Ident])

The fallback case for non-matching enum variants. The slice is the identifiers holding the variant index value for each of the Self arguments.

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

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

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion 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:

  • Single: 12 bytes
  • Combine: 28 bytes
  • Fieldless: 0 bytes
  • EnumNonMatching: 28 bytes