message: [crispy] BufferObject: cleanup
diff: #include <fmt/format.h>
  +#include <cassert>
  +
  using std::destroy_n;
  using std::move;
  using std::size_t;
  @@ -32,13 +34,13 @@ auto const inline BufferObjectLog = logstore::Category("BufferObject",
  BufferFragment::BufferFragment(BufferObjectPtr buffer, size_t offset, size_t size) noexcept:
  buffer_ { move(buffer) }, region_ { buffer_->data() + offset, size }
  {
  - assert(buffer_->begin() <= region_.begin() && region_.end() <= buffer_->end());
  + assert(buffer_->begin() <= &*region_.begin() && &*region_.end() <= buffer_->end());
  }
  BufferFragment::BufferFragment(BufferObjectPtr buffer, string_view region) noexcept:
  buffer_ { move(buffer) }, region_ { region }
  {
  - assert(buffer_->begin() <= region_.begin() && region_.end() <= buffer_->end());
  + assert(buffer_->begin() <= &*region_.begin() && &*region_.end() <= buffer_->end());
  }
  BufferObject::BufferObject(size_t capacity) noexcept:
  