Add note about possible allocation-sharing to Arc/Rc<str/[T]/CStr>::default.

1 files changed, 4 insertions, 0 deletions

diff --git a/library/alloc/src/ffi/c_str.rs b/library/alloc/src/ffi/c_str.rs
index 19dd90eb81f..3b56a5717e2 100644
--- a/library/alloc/src/ffi/c_str.rs
+++ b/library/alloc/src/ffi/c_str.rs
@@ -914,6 +914,8 @@ impl From<&CStr> for Rc<CStr> {
 #[stable(feature = "more_rc_default_impls", since = "CURRENT_RUSTC_VERSION")]
 impl Default for Arc<CStr> {
     /// Creates an empty CStr inside an Arc
+    ///
+    /// This may or may not share an allocation with other Arcs.
     #[inline]
     fn default() -> Self {
         let c_str: &CStr = Default::default();
@@ -925,6 +927,8 @@ impl Default for Arc<CStr> {
 #[stable(feature = "more_rc_default_impls", since = "CURRENT_RUSTC_VERSION")]
 impl Default for Rc<CStr> {
     /// Creates an empty CStr inside an Rc
+    ///
+    /// This may or may not share an allocation with other Rcs on the same thread.
     #[inline]
     fn default() -> Self {
         let c_str: &CStr = Default::default();