WINAPI utf8 to wchar conversion

int utf8_to_wide_char(const char* UTF8_string, wchar_t** OUT_wide_chars, size_t* OUT_size)
{
    if (!UTF8_string)
        return 1;

    const size_t length = (size_t)MultiByteToWideChar(CP_UTF8, 0, UTF8_string, -1, NULL, 0);

    wchar_t* wide_characters = (wchar_t*)malloc(length * sizeof(wchar_t));
    if (!wide_characters)
    {
        return 1;
    }

    if (length > 0)
    {
        MultiByteToWideChar(CP_UTF8, 0, UTF8_string, -1, wide_characters, length);
    }

    if (OUT_wide_chars)
        *OUT_wide_chars = wide_characters;

    if (OUT_size)
        *OUT_size = length;

    return 0;
}