| 4163 | return m_cache; |
| 4164 | } |
| 4165 | bool next() override { |
| 4166 | const auto success = m_generator.next(); |
| 4167 | if (success) { |
| 4168 | m_cache = m_function(m_generator.get()); |
| 4169 | } |
| 4170 | return success; |
| 4171 | } |
| 4172 | }; |
| 4173 | |
| 4174 | #if defined(__cpp_lib_is_invocable) && __cpp_lib_is_invocable >= 201703 |