if constexpr()

in src/iceberg/expected.h [1348:1382]

• 31 lines of code
• 7 McCabe index (conditional complexity)

      if constexpr (std::is_nothrow_move_constructible_v<E>) {
        E tmp(std::move(rhs.error()));
        if constexpr (!std::is_trivially_destructible_v<E>) {
          rhs.error().~E();
        }

        if constexpr (std::is_nothrow_move_constructible_v<T>) {
          std::construct_at(std::addressof(rhs.m_val), std::move(this->m_val));
        } else {
          expected_detail::ReinitGuard<E> guard{std::addressof(rhs.error()),
                                                std::addressof(tmp)};
          std::construct_at(std::addressof(rhs.m_val), std::move(this->m_val));
          guard._target = nullptr;
        }

        if constexpr (!std::is_trivially_destructible_v<T>) {
          this->m_val.~T();
        }
        std::construct_at(std::addressof(this->error()), std::move(tmp));
      } else {
        T tmp(std::move(this->m_val));
        if constexpr (!std::is_trivially_destructible_v<T>) {
          this->m_val.~T();
        }

        expected_detail::ReinitGuard<T> guard{std::addressof(this->m_val),
                                              std::addressof(tmp)};
        std::construct_at(std::addressof(this->error()), std::move(rhs.error()));
        guard._target = nullptr;

        if constexpr (!std::is_trivially_destructible_v<E>) {
          rhs.error().~E();
        }
        std::construct_at(std::addressof(rhs.m_val), std::move(tmp));
      }