systmpdir

static VALUE
etc_systmpdir(void)
{
#ifdef _WIN32
    WCHAR path[_MAX_PATH];
    UINT len = rb_w32_system_tmpdir(path, numberof(path));
    if (!len) return Qnil;
    return rb_w32_conv_from_wchar(path, rb_filesystem_encoding());
#else
    return rb_filesystem_str_new_cstr("/tmp");
#endif
}