crate fn is_closure_fn_mut(
        &self,
        infcx: &InferCtxt<'_, '_, 'tcx>,
        fr: RegionVid,
    ) -> bool {
        if let Some(ty::ReFree(free_region)) = self.to_error_region(fr) {
            if let ty::BoundRegion::BrEnv = free_region.bound_region {
                if let DefiningTy::Closure(def_id, substs) = self.universal_regions.defining_ty {
                    let closure_kind_ty = substs.closure_kind_ty(def_id, infcx.tcx);
                    return Some(ty::ClosureKind::FnMut) == closure_kind_ty.to_opt_closure_kind();
                }
            }
        }

        false
    }
/// Returns `true` if a closure is inferred to be an `FnMut` closure.
Returns `true` if a closure is inferred to be an `FnMut` closure.
Returns ` true ` if a closure is inferred to be an ` FnMut ` closure .
crate fn is_closure_fn_mut(
        &self,
        infcx: &InferCtxt<'_, '_, 'tcx>,
        fr: RegionVid,
    ) -> bool {
        if let Some(ty::ReFree(free_region)) = self.to_error_region(fr) {
            if let ty::BoundRegion::BrEnv = free_region.bound_region {
                if let DefiningTy::Closure(def_id, substs) = self.universal_regions.defining_ty {
                    let closure_kind_ty = substs.closure_kind_ty(def_id, infcx.tcx);
                    return Some(ty::ClosureKind::FnMut) == closure_kind_ty.to_opt_closure_kind();
                }
            }
        }
        false
    }
crate fn is_closure_fn_mut ( & self , infcx : & InferCtxt < ' _ , ' _ , ' tcx > , fr : RegionVid , ) -> bool { if let Some ( ty :: ReFree ( free_region ) ) = self . to_error_region ( fr ) { if let ty :: BoundRegion :: BrEnv = free_region . bound_region { if let DefiningTy :: Closure ( def_id , substs ) = self . universal_regions . defining_ty { let closure_kind_ty = substs . closure_kind_ty ( def_id , infcx . tcx ) ; return Some ( ty :: ClosureKind :: FnMut ) == closure_kind_ty . to_opt_closure_kind ( ) ; } } } false }
Returns `true` if a closure is inferred to be an `FnMut` closure.
Returns ` true ` if a closure is inferred to be an ` FnMut ` closure .
&self
infcx
&InferCtxt<'_, '_, 'tcx>
fr
RegionVid