UNICODE::TOLOWER(3)

💖 UNICODE::TOLOWER — bestie's guide to casing, but make it unicode 💖

okay so this is a page from the Courier Unicode Library, and it's all about unicode::tolower, unicode::toupper, and unicode::totitle — aka the unicode version of tolower(3) and toupper(3) and totitle(3) (if there was such a thing, which, valid question, and here we are 🫶).

---

✨ SYNOPSIS ✨

no thoughts, just headers:

#include <courier-unicode.h>

std::string unicode::tolower(const std::string &string);

std::string unicode::tolower(const std::string &string,
                             const std::string &charset);

std::u32string unicode::tolower(const std::u32string_view &u);

std::string unicode::toupper(const std::string &string);

std::string unicode::toupper(const std::string &string,
                             const std::string &charset);

std::u32string unicode::toupper(const std::u32string_view &u);

std::string unicode::totitle(const std::string &string);

std::string unicode::totitle(const std::string &string,
                             const std::string &charset);

std::u32string unicode::totitle(const std::u32string_view &u);

like… nine whole ways to do the thing. we love options 💅

---

🌸 DESCRIPTION 🌸

here's the tea, bestie ☕

these functions take your string parameter — which is in charset, or in unicode_default_chset(3) if you didn't say otherwise — and convert it to unicode ✨. then every single character gets swapped out for its unicode_lc(3), unicode_uc(3), or unicode_tc(3) version (lowercase, uppercase, titlecase — pick your fighter). then it converts everything back into the same character set it started in, and hands you the resulting string. it's giving round trip, it's giving "leave no trace" 🦋

and if you pass a const std::u32string_view & directly? it converts that accordingly too, no charset detour needed, and returns the converted unicode string. main character energy, honestly 👑

ngl the character-for-character swap is the whole plot. no surprises, no side quests. it converts, it swaps, it converts back, it returns. periodt.

---

👀 SEE ALSO 👀

• courier-unicode(7) — go read it, iykyk

---

🎀 AUTHOR 🎀

Sam Varshavchik — Author 💜

---

okay that's the whole page!! this is the Courier Unicode Library, page dated 04/12/2026, and honestly? iconic. slay, stay cased correctly, and remember: your strings deserve unicode ✨🦋💖