Struct Lifetime

pub struct Lifetime {
    pub hir_id: HirId,
    pub ident: Ident,
    pub res: LifetimeName,
    pub is_anon_in_path: IsAnonInPath,
}

A lifetime. The valid field combinations are non-obvious. The following example shows some of them. See also the comments on LifetimeName.

#[repr(C)]
struct S<'a>(&'a u32);       // res=Param, name='a, IsAnonInPath::No
unsafe extern "C" {
    fn f1(s: S);             // res=Param, name='_, IsAnonInPath::Yes
    fn f2(s: S<'_>);         // res=Param, name='_, IsAnonInPath::No
    fn f3<'a>(s: S<'a>);     // res=Param, name='a, IsAnonInPath::No
}

struct St<'a> { x: &'a u32 } // res=Param, name='a, IsAnonInPath::No
fn f() {
    _ = St { x: &0 };        // res=Infer, name='_, IsAnonInPath::Yes
    _ = St::<'_> { x: &0 };  // res=Infer, name='_, IsAnonInPath::No
}

struct Name<'a>(&'a str);    // res=Param,  name='a, IsAnonInPath::No
const A: Name = Name("a");   // res=Static, name='_, IsAnonInPath::Yes
const B: &str = "";          // res=Static, name='_, IsAnonInPath::No
static C: &'_ str = "";      // res=Static, name='_, IsAnonInPath::No
static D: &'static str = ""; // res=Static, name='static, IsAnonInPath::No

trait Tr {}
fn tr(_: Box<dyn Tr>) {}     // res=ImplicitObjectLifetimeDefault, name='_, IsAnonInPath::No

// (commented out because these cases trigger errors)
// struct S1<'a>(&'a str);   // res=Param, name='a, IsAnonInPath::No
// struct S2(S1);            // res=Error, name='_, IsAnonInPath::Yes
// struct S3(S1<'_>);        // res=Error, name='_, IsAnonInPath::No
// struct S4(S1<'a>);        // res=Error, name='a, IsAnonInPath::No

Fields

hir_id: HirId

ident: Ident

Either a named lifetime definition (e.g. 'a, 'static) or an anonymous lifetime ('_, either explicitly written, or inserted for things like &type).

res: LifetimeName

Semantics of this lifetime.

is_anon_in_path: IsAnonInPath

Is the lifetime anonymous and in a path? Used only for error suggestions. See Lifetime::suggestion for example use.

Implementations

impl Lifetime

pub fn new( hir_id: HirId, ident: Ident, res: LifetimeName, is_anon_in_path: IsAnonInPath, ) -> Lifetime

pub fn is_elided(&self) -> bool

pub fn is_anonymous(&self) -> bool

pub fn suggestion(&self, new_lifetime: &str) -> (Span, String)

Trait Implementations

impl Clone for Lifetime

fn clone(&self) -> Lifetime

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Lifetime

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

Formats the value using the given formatter.

impl Display for Lifetime

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

Formats the value using the given formatter.

impl<__CTX> HashStable<__CTX> for Lifetime

where __CTX: HashStableContext,

fn hash_stable(&self, __hcx: &mut __CTX, __hasher: &mut StableHasher)

impl Copy for Lifetime

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: 28 bytes