[#boost-urls-grammar-ci_hash] = xref:boost/urls/grammar/ci_hash.adoc[boost::urls::grammar::ci_hash] :relfileprefix: ../../../ :mrdocs: A case‐insensitive hash function object for strings == Synopsis Declared in `<https://www.github.com/boostorg/url/blob/develop/include/boost/url/grammar/ci_string.hpp#L287[boost/url/grammar/ci_string.hpp]>` [source,cpp,subs="verbatim,replacements,macros,-callouts"] ---- using ci_hash = /* implementation-defined */; ---- == Description The hash function is non‐cryptographic and not hardened against algorithmic complexity attacks. This is a suitable hash function for unordered containers. The function is defined only for strings containing low‐ASCII characters. == Example [,cpp] ---- boost::unordered_map< std::string, std::string, ci_hash, ci_equal > m1; std::unordered_map < std::string, std::string, ci_hash, ci_equal > m2; // (since C++20) ---- == See Also xref:boost/urls/grammar/ci_equal.adoc[`ci_equal`], xref:boost/urls/grammar/ci_less.adoc[`ci_less`]. [.small]#Created with https://www.mrdocs.com[MrDocs]#