We updated to clang-tidy 18 in https://github.com/Project-OSRM/osrm-backend/pull/6919/files and disabled some of newly introduced warnings. This issue is to track progress on fixing them:

• bugprone-chained-comparison
• bugprone-incorrect-enable-if
• bugprone-switch-missing-default-case
• bugprone-empty-catch
• bugprone-unused-return-value
• misc-include-cleaner
• performance-noexcept-swap
• performance-enum-size
• performance-avoid-endl
• readability-redundant-inline-specifier
• readability-avoid-nested-conditional-operator
• readability-avoid-return-with-void-value
• readability-redundant-casting

NOTE: some of them may be not actually very useful