Module list

Mutable List container sharing the ffi.List object layout with C++.

ListObj mirrors C++ ListObj (Object followed by TVMFFISeqCell), so Rust reads and edits the element cells in place: reads, List::set, List::insert, List::remove, List::remove_range, List::truncate, List::reverse, List::clear and iteration touch the buffer directly, with no FFI call. The object and its element buffer are allocated by the C++ runtime (ffi.List), because the buffer is a separate allocation that data_deleter has to free with the allocator that produced it. For the same reason, growing a full buffer is left to C++ (ffi.ListReserve), which the mutators call only when there is no spare capacity; the elements themselves are then written in place.

A List is a shared handle, as in C++ and Python: cloning it bumps the refcount, and a mutation through one handle is seen through all of them. That is why the mutating methods take &self, and why elements are returned by value rather than by reference. Like its C++ counterpart it is not synchronized; the raw buffer pointer keeps it !Send and !Sync.

Any conversions follow C++ SeqTypeTraitsBase (seq_base.h): an ffi.List whose elements all match T is shared; an ffi.Array, or a list whose elements need converting, is copied into a new list.

Structs

• List
  Mutable, reference-counted sequence of T, sharing its underlying ListObj with C++. Cloning is cheap (it bumps the refcount) and yields a handle to the same list.
• ListIterator
  Iterator over a List, created by List::iter. Each step yields Ok(T), or the TYPE_ERROR List::get would give when the element at that position is not a T (another handle to the same list may have put it there), and then moves on to the next element. It re-reads the length on every step, so it stays in bounds if the list is mutated meanwhile; iterating from the back (rev) pins the end at the first back step.
• ListObj
  Container object for List, laid out as C++ ListObj. Unlike ffi.Array, the element buffer data is a separate allocation that the C++ runtime replaces when the list grows.