Struct rustc_trait_selection::traits::ObligationCause

source · 
pub struct ObligationCause<'tcx> {
    pub span: Span,
    pub body_id: HirId,
    code: InternedObligationCauseCode<'tcx>,
}
Expand description

The reason why we incurred this obligation; used for error reporting.

Non-misc ObligationCauseCodes are stored on the heap. This gives the best trade-off between keeping the type small (which makes copies cheaper) while not doing too many heap allocations.

We do not want to intern this as there are a lot of obligation causes which only live for a short period of time.

Fields§

§span: Span§body_id: HirId

The ID of the fn body that triggered this obligation. This is used for region obligations to determine the precise environment in which the region obligation should be evaluated (in particular, closures can add new assumptions). See the field region_obligations of the FulfillmentContext for more information.

§code: InternedObligationCauseCode<'tcx>

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.

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: 24 bytes