proc av_tree_destroy(t: ptr AVTreeNode) {.importc, cdecl, ...raises: [], tags: [],
    forbids: [].}

proc av_tree_enumerate(t: ptr AVTreeNode; opaque: pointer;
                       cmp: proc (opaque, elem: pointer);
                       enu: proc (opaque, elem: pointer)) {.importc, cdecl,
    ...raises: [], tags: [], forbids: [].}

proc av_tree_find(root: ptr AVTreeNode; key: pointer;
                  cmp: proc (key, b: pointer): cint; next: ptr pointer): pointer {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}

proc av_tree_insert(rootp: ptr ptr AVTreeNode; key: pointer;
                    cmp: proc (key, b: pointer): cint; next: ptr ptr AVTreeNode): pointer {.
    importc, cdecl, ...raises: [], tags: [], forbids: [].}

proc av_tree_node_alloc(): ptr AVTreeNode {.importc, cdecl, ...raises: [],
    tags: [], forbids: [].}