Function operator==

common/memory.h:212–216

Tests whether two owners have ownership over the same data, that is they are co-owners.

  // Tests whether two owners have ownership over the same data, that is they
  // are co-owners.
  friend bool operator==(const Owner& lhs, const Owner& rhs) noexcept {
    // A reference count and arena can never occupy the same memory address, so
    // we can compare for equality without masking off the bits.
    return lhs.ptr_ == rhs.ptr_;
  }

 private:
  template <typename T>