Enum chalk_ir::Constraint [−][src]
pub enum Constraint<I: Interner> { LifetimeOutlives(Lifetime<I>, Lifetime<I>), TypeOutlives(Ty<I>, Lifetime<I>), }
Expand description
A constraint on lifetimes.
When we search for solutions within the trait system, we essentially ignore lifetime constraints, instead gathering them up to return with our solution for later checking. This allows for decoupling between type and region checking in the compiler.
Variants
Outlives constraint 'a: 'b
, indicating that the value of 'a
must be
a superset of the value of 'b
.
Type outlives constraint T: 'a
, indicating that the type T
must live
at least as long as the value of 'a
.
Trait Implementations
Cast a value to type T
.
type Result = Constraint<I>
type Result = Constraint<I>
The type of value that will be produced once folding is done.
Typically this is Self
, unless Self
contains borrowed
values, in which case owned values are produced (for example,
one can fold over a &T
value where T: Fold
, in which case
you get back a T
, not a &T
). Read more
Apply the given folder folder
to self
; binders
is the
number of binders that are in scope when beginning the
folder. Typically binders
starts as 0, but is adjusted when
we encounter Binders<T>
in the IR or other similar
constructs. Read more
type Interner = I
type Interner = I
The interner associated with the type.
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
This method tests for !=
.
fn visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
fn visit_with<'i, B>(
&self,
visitor: &mut dyn Visitor<'i, I, BreakTy = B>,
outer_binder: DebruijnIndex
) -> ControlFlow<B> where
I: 'i,
Apply the given visitor visitor
to self
; binders
is the
number of binders that are in scope when beginning the
visitor. Typically binders
starts as 0, but is adjusted when
we encounter Binders<T>
in the IR or other similar
constructs. Read more
impl<I: Interner> Copy for Constraint<I> where
I::InternedLifetime: Copy,
I::InternedType: Copy,
Auto Trait Implementations
impl<I> RefUnwindSafe for Constraint<I> where
<I as Interner>::InternedLifetime: RefUnwindSafe,
<I as Interner>::InternedType: RefUnwindSafe,
impl<I> Send for Constraint<I> where
<I as Interner>::InternedLifetime: Send,
<I as Interner>::InternedType: Send,
impl<I> Sync for Constraint<I> where
<I as Interner>::InternedLifetime: Sync,
<I as Interner>::InternedType: Sync,
impl<I> Unpin for Constraint<I> where
<I as Interner>::InternedLifetime: Unpin,
<I as Interner>::InternedType: Unpin,
impl<I> UnwindSafe for Constraint<I> where
<I as Interner>::InternedLifetime: UnwindSafe,
<I as Interner>::InternedType: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
Cast a value to type U
using CastTo
.
impl<T, I> CouldMatch<T> for T where
T: Zip<I> + HasInterner<Interner = I> + ?Sized,
I: Interner,
impl<T, I> CouldMatch<T> for T where
T: Zip<I> + HasInterner<Interner = I> + ?Sized,
I: Interner,
Checks whether self
and other
could possibly match.
Shifts this term in one level of binders.
Shifts a term valid at outer_binder
so that it is
valid at the innermost binder. See DebruijnIndex::shifted_in_from
for a detailed explanation. Read more
Shifts a term valid at the innermost binder so that it is
valid at outer_binder
. See DebruijnIndex::shifted_out_to
for a detailed explanation. Read more
Shifts this term out one level of binders.