Enum TypeParam 

pub enum TypeParam {
    Type {
        name: String,
        span: Span,
        doc_comment: Option<DocComment>,
        default_type: Option<TypeAnnotation>,
        trait_bounds: Vec<TypePath>,
    },
    Const {
        name: String,
        span: Span,
        doc_comment: Option<DocComment>,
        ty: TypeAnnotation,
        default: Option<Expr>,
    },
}

A generic parameter on a function, type, trait or impl header.

Two variants:

• TypeParam::Type — the classic type-level parameter (<T>, <T: Bound>, <T = DefaultType>).
• TypeParam::Const — a value-level const generic parameter (<const N: int>, <const N: int = 4>). Added in B.2 of the const-generics track; B.3 binds const args at monomorphization and B.4 substitutes them into specialized bodies. Until then most consumers treat const params as a placeholder — the AST captures the name, declared type, and optional default expression so later phases can wire them end-to-end.

Variants

Type

A type parameter: T, T: Bound, T = DefaultType.

Fields

name: String

span: Span

doc_comment: Option<DocComment>

default_type: Option<TypeAnnotation>

Default type argument: T = int

trait_bounds: Vec<TypePath>

Trait bounds: T: Comparable + Displayable

Const

A const generic parameter: const N: int, const N: int = 4.

Parsed in B.1/B.2. Monomorphization (B.3) and body substitution (B.4) are not yet implemented — most compiler passes currently treat this variant as a stub / placeholder.

Fields

name: String

span: Span

doc_comment: Option<DocComment>

ty: TypeAnnotation

Declared type: const N: int.

default: Option<Expr>

Optional default value expression: = 4.

Implementations

impl TypeParam

pub fn name(&self) -> &str

The parameter’s declared name (T or N), common to both variants.

pub fn span(&self) -> &Span

The parameter’s source span, common to both variants.

pub fn doc_comment(&self) -> Option<&DocComment>

The parameter’s attached doc comment, common to both variants.

pub fn trait_bounds(&self) -> &[TypePath]

Trait bounds, only present on the Type variant.

Returns an empty slice for const generics (they have no bounds).

pub fn default_type(&self) -> Option<&TypeAnnotation>

Default type argument, only meaningful for the Type variant.

pub fn is_const(&self) -> bool

True iff this is a const generic parameter.

pub fn simple(name: impl Into<String>) -> Self

Convenience constructor for a plain type parameter with no bounds or default — the shape that stdlib bootstrap / method desugaring most often needs.

Trait Implementations

impl Clone for TypeParam

fn clone(&self) -> TypeParam

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TypeParam

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for TypeParam

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for TypeParam

fn eq(&self, other: &Self) -> 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 Serialize for TypeParam

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.