//en.cppreference.com/w/c/string/wide/wmemcpy.html
#include <stdio.h>
#include <wchar.h>
#include <locale.h>
int main(void)
{
wchar_t from1[] = L"नमस्ते";
size_t sz1 = sizeof from1 / sizeof *from1;
wchar_t from2[] = L"Բարև";
size_t sz2 = sizeof from2 / sizeof *from2;
wchar_t to[sz1 + sz2];
wmemcpy(to, from1, sz1); // copy from1, along with its null terminator
wmemcpy(to + sz1, from2, sz2); // append from2, along with its null terminator
setlocale(LC_ALL, "en_US.utf8");
printf("Wide array contains: ");
for(size_t n = 0; n < sizeof to / sizeof *to; ++n)
if(to[n])
printf("%lc", to[n]);
else
printf("\\0");
printf("\n");
}