impl Error for TryReserveError

Author: clarfonthey

src/lib.rs

@@ -174,3 +174,21 @@ pub enum TryReserveError {
         layout: stdalloc::alloc::Layout,
     },
 }
+
+// matches stdalloc::collections::TryReserveError
+impl core::fmt::Display for TryReserveError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.write_str("memory allocation failed")?;
+        let reason = match self {
+            TryReserveError::CapacityOverflow => {
+                " because the computed capacity exceeded the collection's maximum"
+            }
+            TryReserveError::AllocError { .. } => {
+                " because the memory allocator returned an error"
+            }
+        };
+        f.write_str(reason)
+    }
+}
+
+impl core::error::Error for TryReserveError {}