class DispatchLoaderBase
  {
  public:
    DispatchLoaderBase() = default;
    DispatchLoaderBase( std::nullptr_t )
#if !defined( NDEBUG )
      : m_valid( false )
#endif
    {}

#if !defined( NDEBUG )
    size_t getVkHeaderVersion() const
    {
      VULKAN_HPP_ASSERT( m_valid );
      return vkHeaderVersion;
    }

  private:
    size_t vkHeaderVersion = VK_HEADER_VERSION;
    bool   m_valid         = true;
#endif
  };