LazySegmentTree[S; F] = ref object
  default: S
  merge: proc (x: S; y: S): S
  arr*: seq[S]
  lazy*: seq[F]
  mapping: proc (f: F; x: S): S
  composition: proc (f, g: F): F
  id: F
  lastnode: int
  log: int
  length: int

CPLIB_COLLECTIONS_LAZYSEGTREE = 1

proc `$`[S, F](self: var LazySegmentTree[S, F]): string

proc `[]=`[S, F](self: var LazySegmentTree[S, F]; p: Natural; val: S)

proc `[]`[S, F](self: var LazySegmentTree[S, F]; p: Natural): S

proc `[]`[S, F](self: var LazySegmentTree[S, F]; segment: HSlice[int, int]): S

proc apply[S, F](self: var LazySegmentTree[S, F]; q_left, q_right: int; f: F)

proc apply[S, F](self: var LazySegmentTree[S, F]; segment: HSlice[int, int];
                 f: F)

proc get[S, F](self: var LazySegmentTree[S, F]; q_left, q_right: int): S

proc get[S, F](self: var LazySegmentTree[S, F]; segment: HSlice[int, int]): S

proc initLazySegmentTree[S, F](v_or_n: int or seq[S];
                               merge: proc (x: S; y: S): S; default: S;
                               mapping: proc (f: F; x: S): S;
                               composition: proc (f, g: F): F; id: F): LazySegmentTree[
    S, F]

proc len[S, F](self: var LazySegmentTree[S, F]): int

proc update[S, F](self: var LazySegmentTree[S, F]; p: Natural; val: S)

template newLazySegWith(v_or_n, merge, default, mapping, composition, id: untyped): untyped