X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=library%2Fcore%2Fsrc%2Flib.rs;h=6dfe36e6926ef057759d23d198abd83910688ada;hb=dc3e59cb3fe05ebd752d3a2269f501c00327be22;hp=8790649abe6f1b90433171f95816072ecd05a4ca;hpb=685c77305c4109508b52d6642a7d11b9005a0abb;p=rust.git

diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 8790649abe6..6dfe36e6926 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -95,6 +95,7 @@
 #![warn(missing_docs)]
 #![allow(explicit_outlives_requirements)]
 #![allow(incomplete_features)]
+#![cfg_attr(not(bootstrap), warn(multiple_supertrait_upcastable))]
 //
 // Library features:
 #![feature(const_align_offset)]
@@ -235,6 +236,7 @@
 #![feature(unsized_fn_params)]
 #![feature(asm_const)]
 #![feature(const_transmute_copy)]
+#![cfg_attr(not(bootstrap), feature(multiple_supertrait_upcastable))]
 //
 // Target features:
 #![feature(arm_target_feature)]