Struct rustc_trait_selection::traits::util::traits::Obligation
source · [−]pub struct Obligation<'tcx, T> {
pub cause: ObligationCause<'tcx>,
pub param_env: ParamEnv<'tcx>,
pub predicate: T,
pub recursion_depth: usize,
}Expand description
An Obligation represents some trait reference (e.g., i32: Eq) for
which the “impl_source” must be found. The process of finding an “impl_source” is
called “resolving” the Obligation. This process consists of
either identifying an impl (e.g., impl Eq for i32) that
satisfies the obligation, or else finding a bound that is in
scope. The eventual result is usually a Selection (defined below).
Fields
cause: ObligationCause<'tcx>The reason we have to prove this thing.
param_env: ParamEnv<'tcx>The environment in which we should prove this thing.
predicate: TThe thing we are trying to prove.
recursion_depth: usizeIf we started proving this as a result of trying to prove something else, track the total depth to ensure termination. If this goes over a certain threshold, we abort compilation – in such cases, we can not say whether or not the predicate holds for certain. Stupid halting problem; such a drag.
Auto Trait Implementations
impl<'tcx, T> !RefUnwindSafe for Obligation<'tcx, T>
impl<'tcx, T> !Send for Obligation<'tcx, T>
impl<'tcx, T> !Sync for Obligation<'tcx, T>
impl<'tcx, T> Unpin for Obligation<'tcx, T> where
T: Unpin,
impl<'tcx, T> !UnwindSafe for Obligation<'tcx, T>
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<'tcx, T> Subst<'tcx> for T where
T: TypeFoldable<'tcx>,
impl<'tcx, T> Subst<'tcx> for T where
T: TypeFoldable<'tcx>,
pub fn subst_spanned(
self,
tcx: TyCtxt<'tcx>,
substs: &[GenericArg<'tcx>],
span: Option<Span>
) -> T
fn subst(self, tcx: TyCtxt<'tcx>, substs: &[GenericArg<'tcx>]) -> Self
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcepub fn to_owned(&self) -> T
pub fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
sourcepub fn clone_into(&self, target: &mut T)
pub fn clone_into(&self, target: &mut T)
toowned_clone_into)Uses borrowed data to replace owned data, usually by cloning. Read more
Layout
Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.