Converts the given wide character to lowercase, if possible.

If the value ofch is neither representable as awchar_t nor equal to the value of the macroWEOF, the behavior is undefined.

[edit]Parameters

[edit]Return value

Lowercase version ofch or unmodifiedch if no lowercase version is listed in the current C locale.

[edit]Notes

Only 1:1 character mapping can be performed by this function, e.g. the Greek uppercase letter'Σ' has two lowercase forms, depending on the position in a word:'σ' and'ς'. A call tostd::towlower cannot be used to obtain the correct lowercase form in this case.

ISO 30112 specifies which pairs of Unicode characters are included in this mapping.

[edit]Example

#include <clocale>#include <cwctype>#include <iostream> int main(){wchar_t c= L'\u0190';// Latin capital open E ('Ɛ') std::cout<<std::hex<<std::showbase;std::cout<<"in the default locale, towlower("<<static_cast<std::wint_t>(c)<<") = "<< std::towlower(c)<<'\n';std::setlocale(LC_ALL,"en_US.utf8");std::cout<<"in Unicode locale, towlower("<<static_cast<std::wint_t>(c)<<") = "<< std::towlower(c)<<'\n';}

in the default locale, towlower(0x190) = 0x190in Unicode locale, towlower(0x190) = 0x25b

[edit]See also

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