Multibyte char to Wide char

const char *source = "Hello World!";
int buffer_size = MultiByteToWideChar(0, 0, source, -1, NULL, NULL) * sizeof(wchar_t);
WCHAR *destination = new WCHAR[buffer_size]; // allocate memory
MultiByteToWideChar(0, 0, source, -1, destination, buffer_size);