Function rustc_trait_selection::traits::wf::trait_obligations

pub fn trait_obligations<'a, 'tcx>(
    infcx: &InferCtxt<'a, 'tcx>, 
    param_env: ParamEnv<'tcx>, 
    body_id: HirId, 
    trait_ref: &TraitRef<'tcx>, 
    span: Span, 
    item: Option<&'tcx Item<'tcx>>
) -> Vec<PredicateObligation<'tcx>>

Returns the obligations that make this trait reference well-formed. For example, if there is a trait Set defined like trait Set<K:Eq>, then the trait reference Foo: Set<Bar> is WF if Bar: Eq.