Enum rustc_infer::traits::ImplSource
source · pub enum ImplSource<'tcx, N> {
UserDefined(ImplSourceUserDefinedData<'tcx, N>),
Param(Vec<N, Global>),
Builtin(BuiltinImplSource, Vec<N, Global>),
}
Expand description
Given the successful resolution of an obligation, the ImplSource
indicates where the impl comes from.
For example, the obligation may be satisfied by a specific impl (case A), or it may be relative to some bound that is in scope (case B).
impl<T:Clone> Clone<T> for Option<T> { ... } // Impl_1
impl<T:Clone> Clone<T> for Box<T> { ... } // Impl_2
impl Clone for i32 { ... } // Impl_3
fn foo<T: Clone>(concrete: Option<Box<i32>>, param: T, mixed: Option<T>) {
// Case A: ImplSource points at a specific impl. Only possible when
// type is concretely known. If the impl itself has bounded
// type parameters, ImplSource will carry resolutions for those as well:
concrete.clone(); // ImplSource(Impl_1, [ImplSource(Impl_2, [ImplSource(Impl_3)])])
// Case B: ImplSource must be provided by caller. This applies when
// type is a type parameter.
param.clone(); // ImplSource::Param
// Case C: A mix of cases A and B.
mixed.clone(); // ImplSource(Impl_1, [ImplSource::Param])
}
The type parameter N
See explanation on ImplSourceUserDefinedData
.
Variants§
UserDefined(ImplSourceUserDefinedData<'tcx, N>)
ImplSource identifying a particular impl.
Param(Vec<N, Global>)
Successful resolution to an obligation provided by the caller
for some type parameter. The Vec<N>
represents the
obligations incurred from normalizing the where-clause (if
any).
Builtin(BuiltinImplSource, Vec<N, Global>)
Successful resolution for a builtin impl.
Auto Trait Implementations§
impl<'tcx, N> !RefUnwindSafe for ImplSource<'tcx, N>
impl<'tcx, N> Send for ImplSource<'tcx, N>where N: Send,
impl<'tcx, N> Sync for ImplSource<'tcx, N>where N: Sync,
impl<'tcx, N> Unpin for ImplSource<'tcx, N>where N: Unpin,
impl<'tcx, N> !UnwindSafe for ImplSource<'tcx, N>
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
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: 48 bytes
Size for each variant:
UserDefined
: 40 bytesParam
: 24 bytesBuiltin
: 40 bytes