Entering !cpp std::array into the search bar redirects me to cppreference.com as intended. However, the search string is not passed correctly, resulting in a 404 error:
The requested URL (/mwiki/index.php?search=std%3A%3Aarray) was not found on this server.
I'd like to get a list of search results from cppreference.com. If their internal search is no longer available, perhaps Kagi should do what DuckDuckGo did and add a site:cppreference.com filter when the user uses the !cpp bang. I wouldn't remove the bang as the search might return eventually. The site has been in maintenance mode for months, so the situation is unclear.