#include <iostream>
#include <cstdlib>
#include <string>
std::string wstring_from_bytes(std::wstring const& wstr)
{
std::size_t const size = sizeof(wstr.c_str());
char *str = new char[size];
std::string temp;
std::wcstombs(str, wstr.c_str(), size);
temp = str;
return temp;
}
int main()
{
std::wstring wstr = L"abcd";
std::string str = wstring_from_bytes(wstr);
std::cout << str;
}
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