16a0d03698
Clarify the guarantees of Vec::as_ptr and Vec::as_mut_ptr when there's no allocation Currently the documentation says they return a pointer to the vector's buffer, which has the implied precondition that the vector allocated some memory. However `Vec`'s documentation also specifies that it won't always allocate, so it's unclear whether the pointer returned is valid in that case. Of course you won't be able to read/write actual bytes to/from it since the capacity is 0, but there's an exception: zero sized read/writes. They are still valid as long as the pointer is not null and the memory it points to wasn't deallocated, but `Vec::as_ptr` and `Vec::as_mut_ptr` don't specify that's not the case. This PR thus specifies they are actually valid for zero sized reads since `Vec` is implemented to hold a dangling pointer in those cases, which is neither null nor was deallocated. |
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| .. | ||
| alloc | ||
| backtrace@4e5a3f7292 | ||
| core | ||
| panic_abort | ||
| panic_unwind | ||
| portable-simd | ||
| proc_macro | ||
| profiler_builtins | ||
| rtstartup | ||
| rustc-std-workspace-alloc | ||
| rustc-std-workspace-core | ||
| rustc-std-workspace-std | ||
| std | ||
| stdarch@28335054b1 | ||
| test | ||
| unwind | ||