Enum GenericParamDefKind

pub enum GenericParamDefKind {
    Lifetime {
        outlives: Vec<String>,
    },
    Type {
        bounds: Vec<GenericBound>,
        default: Option<Type>,
        is_synthetic: bool,
    },
    Const {
        type_: Type,
        default: Option<String>,
    },
}

The kind of a GenericParamDef.

Variants

Lifetime

Denotes a lifetime parameter.

Fields

outlives: Vec<String>

Lifetimes that this lifetime parameter is required to outlive.

fn f<'a, 'b, 'resource: 'a + 'b>(a: &'a str, b: &'b str, res: &'resource str) {}
//                      ^^^^^^^

Type

Denotes a type parameter.

Fields

bounds: Vec<GenericBound>

Bounds applied directly to the type. Note that the bounds from where clauses that constrain this parameter won’t appear here.

fn default2<T: Default>() -> [T; 2] where T: Clone { todo!() }
//             ^^^^^^^

default: Option<Type>

The default type for this parameter, if provided, e.g.

trait PartialEq<Rhs = Self> {}
//                    ^^^^

is_synthetic: bool

This is normally false, which means that this generic parameter is declared in the Rust source text.

If it is true, this generic parameter has been introduced by the compiler behind the scenes.

Example

Consider

pub fn f(_: impl Trait) {}

The compiler will transform this behind the scenes to

pub fn f<impl Trait: Trait>(_: impl Trait) {}

In this example, the generic parameter named impl Trait (and which is bound by Trait) is synthetic, because it was not originally in the Rust source text.

Const

Denotes a constant parameter.

Fields

type_: Type

The type of the constant as declared.

default: Option<String>

The stringified expression for the default value, if provided. It’s not guaranteed that it’ll match the actual source code for the default value.

Trait Implementations

impl Clone for GenericParamDefKind

fn clone(&self) -> GenericParamDefKind

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for GenericParamDefKind

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for GenericParamDefKind

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for GenericParamDefKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for GenericParamDefKind

fn eq(&self, other: &GenericParamDefKind) -> 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 GenericParamDefKind

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for GenericParamDefKind

impl StructuralPartialEq for GenericParamDefKind

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: 112 bytes

Size for each variant:

• Lifetime: 32 bytes
• Type: 112 bytes
• Const: 112 bytes