Defined in header <cwchar>
wchar_t* wmemset( wchar_t* dest, wchar_t ch, std::size_t count );

Copies the wide character ch into each of the first count wide characters of the wide character array pointed to by dest.

If overflow occurs, the behavior is undefined.

If count is zero, the function does nothing.


dest - pointer to the wide character array to fill
ch - fill wide character
count - number of wide characters to fill

Return value

Returns a copy of dest.


This function is not locale-sensitive and pays no attention to the values of the wchar_t objects it writes: nulls as well as invalid wide characters are written too.


#include <clocale>
#include <cwchar>
#include <iostream>
#include <locale>
int main()
    wchar_t ar[4] = {L'1', L'2', L'3', L'4'};
    std::wmemset(ar, L'\U0001f34c', 2); // replaces [12] with the 🍌 bananas
    std::wmemset(ar + 2, L'蕉', 2); // replaces [34] with the 蕉 bananas
    std::setlocale(LC_ALL, "en_US.utf8");
    std::wcout << std::wstring(ar, 4) << '\n';

Possible output:


See also

fills a buffer with a character
copies a certain amount of wide characters between two non-overlapping arrays
copy-assigns the given value to N elements in a range
(function template)
C documentation for wmemset

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