Enum ReferenceExpr

pub enum ReferenceExpr {
    Member {
        member: Member,
    },
    Expr {
        const_: Const,
        expr: Expr,
    },
}

Expression that may be a constant or a reference to member field. Often used pattern is having attribute that refer to a field or constant expression.

Examples

/// Peeking first `const` token it decides to parse `Expr` variant.
let re: ReferenceExpr = parse_quote!(const 42);
assert_eq!(re, ReferenceExpr::Expr { const_: parse_quote!(const), expr: parse_quote!(42) });

/// Without `const` token it decides to parse `Member` variant.
let re: ReferenceExpr = parse_quote!(foo);
assert_eq!(re, ReferenceExpr::Member { member: format_ident!("foo").into() });

Variants

Member

Member reference.

Fields

member: Member

Expr

Constant expression

Fields

const_: Const

Const token.

expr: Expr

Trait Implementations

impl Clone for ReferenceExpr

fn clone(&self) -> ReferenceExpr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ReferenceExpr

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

Formats the value using the given formatter.

impl Parse for ReferenceExpr

fn parse(input: ParseStream<'_>) -> Result<Self, Error>

impl PartialEq for ReferenceExpr

fn eq(&self, other: &ReferenceExpr) -> 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 Eq for ReferenceExpr

impl StructuralPartialEq for ReferenceExpr