Defined in header <cwctype>
std::wint_t towctrans( std::wint_t wc, std::wctrans_t desc );

Maps the wide character wc using the current C locale's LC_CTYPE mapping category identified by desc.


ch - the wide character to map
desc - the LC_CTYPE mapping, obtained from a call to std::wctrans

Return value

The mapped value of ch using the mapping identified by desc in LC_CTYPE facet of the current C locale.


The following example demonstrates katakana to hiragana character mapping.

#include <clocale>
#include <cwctype>
#include <iostream>
#include <algorithm>
std::wstring tohira(std::wstring str)
    std::transform(str.begin(), str.end(), str.begin(), [](wchar_t c) {
         return std::towctrans(c, std::wctrans("tojhira"));
    return str;
int main()
    std::setlocale(LC_ALL, "ja_JP.UTF-8");
    std::wstring kana = L"ヒラガナ";
    std::wcout << "katakana characters " << kana
               << " are " << tohira(kana) << " in hiragana\n";


katakana characters ヒラガナ are ひらがな in hiragana

See also

looks up a character mapping category in the current C locale
C documentation for towctrans

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