NAME¶

std::wmemcpy - std::wmemcpy

Synopsis¶

Defined in header <cwchar>
wchar_t* wmemcpy( wchar_t* dest, const wchar_t* src, std::size_t count );

Copies exactly count successive wide characters from the wide character array
pointed to by src to the wide character array pointed to by dest. If the objects
overlap, the behavior is undefined. If count is zero, the function does nothing.

Parameters¶

dest - pointer to the wide character array to copy to
src - pointer to the wide character array to copy from
count - number of wide characters to copy

Return value¶

dest

Notes¶

This function's analog for byte strings is std::strncpy, not std::strcpy.

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

Example¶

// Run this code

#include <clocale>
#include <cwchar>
#include <iostream>
#include <iterator>
#include <locale>

int main(void)
{
const wchar_t from1[] = L"नमसत";
const wchar_t from2[] = L"Բարև";
const std::size_t sz1 = std::size(from1);
const std::size_t sz2 = std::size(from2);
wchar_t to[sz1 + sz2];

std::wmemcpy(to, from1, sz1); // copy from1, along with its null terminator
std::wmemcpy(to + sz1, from2, sz2); // append from2, along with its null terminator

std::setlocale(LC_ALL, "en_US.utf8");
std::wcout.imbue(std::locale("en_US.utf8"));
std::wcout << L"Wide array contains: ";
for (std::size_t n = 0; n < std::size(to); ++n)
if (to[n])
std::wcout << to[n];
else
std::wcout << L"\\0";
std::wcout << L'\n';
}

Possible output:¶

Wide array contains: नमसत\0Բարև\0

See also¶

strncpy copies a certain amount of characters from one string to another
(function)
copies a certain amount of wide characters between two, possibly
wmemmove overlapping, arrays
(function)
C documentation for
wmemcpy