diff options
| -rw-r--r-- | library/alloc/src/string.rs | 5 | ||||
| -rw-r--r-- | library/alloc/src/vec/mod.rs | 6 |
2 files changed, 8 insertions, 3 deletions
diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs index e97c1637fd5..2272c5b7330 100644 --- a/library/alloc/src/string.rs +++ b/library/alloc/src/string.rs @@ -770,7 +770,10 @@ impl String { /// * The first `length` bytes at `buf` need to be valid UTF-8. /// /// Violating these may cause problems like corrupting the allocator's - /// internal data structures. + /// internal data structures. For example, it is normally **not** safe to + /// build a `String` from a pointer to a C `char` array containing UTF-8 + /// _unless_ you are certain that array was originally allocated by the + /// Rust standard library's allocator. /// /// The ownership of `buf` is effectively transferred to the /// `String` which may then deallocate, reallocate or change the diff --git a/library/alloc/src/vec/mod.rs b/library/alloc/src/vec/mod.rs index cbb5b0627b7..3dc8a4fbba8 100644 --- a/library/alloc/src/vec/mod.rs +++ b/library/alloc/src/vec/mod.rs @@ -489,8 +489,10 @@ impl<T> Vec<T> { /// * `length` needs to be less than or equal to `capacity`. /// /// Violating these may cause problems like corrupting the allocator's - /// internal data structures. For example it is **not** safe - /// to build a `Vec<u8>` from a pointer to a C `char` array with length `size_t`. + /// internal data structures. For example it is normally **not** safe + /// to build a `Vec<u8>` from a pointer to a C `char` array with length + /// `size_t`, doing so is only safe if the array was initially allocated by + /// a `Vec` or `String`. /// It's also not safe to build one from a `Vec<u16>` and its length, because /// the allocator cares about the alignment, and these two types have different /// alignments. The buffer was allocated with alignment 2 (for `u16`), but after |