{"ast_node_type":"variable","tokens":[{"end":97,"kind":"keyword","start":0,"text":"let"}]}
            let (index_lane_count, index_lane_ty) = index.layout().ty.simd_size_and_type(fx.tcx);
            let (src_lane_count, src_lane_ty) = src.layout().ty.simd_size_and_type(fx.tcx);
            let (mask_lane_count, mask_lane_ty) = mask.layout().ty.simd_size_and_type(fx.tcx);