Module rustc_trait_selection::traits::select
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Candidate selection. See the rustc dev guide for more information on how this works.
Modules
Candidate assembly.
Confirmation.
Structs
A cache value for the provisional cache: contains the depth-first
number (DFN) and result.
The “provisional evaluation cache” is used to store intermediate cache results
when solving auto traits. Auto traits are unusual in that they can support
cycles. So, for example, a “proof tree” like this would be ok:
Enums
When does the builtin impl for
T: Trait apply?The result of trait evaluation. The order is important
here as the evaluation of a list is the maximum of the
evaluations.
Indicates that trait evaluation caused overflow and in which pass.
The selection process begins by considering all impls, where
clauses, and so forth that might resolve an obligation. Sometimes
we’ll be able to say definitively that (e.g.) an impl does not
apply to the obligation: perhaps it is defined for
usize but the
obligation is for i32. In that case, we drop the impl out of the
list. But the other cases are considered candidates.