Use next_power_of_two from std for calculating height
Use next_power_of_two from std for calculating height


Former-commit-id: 06dab210efa5d14ffdcca2de6cb7430d4f85ed4c
exonum/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum,alekseysidorov/exonum,alekseysidorov/exonum