Function IsNone

common/memory.h:236–236

  constexpr explicit Owner(uintptr_t ptr) noexcept : ptr_(ptr) {}

  static constexpr bool IsNone(uintptr_t ptr) noexcept { return ptr == kNone; }

  static constexpr bool IsArena(uintptr_t ptr) noexcept {
    return (ptr & kArenaBit) != kNone;