$ perl -MEncode -le'
    $_ = decode("UTF-8", encode("UTF-8", "\xA0"));
    print /\s/ ? "space" : "no space";

    $_ = decode("iso-latin-1", encode("iso-latin-1", "\xA0"));
    print /\s/ ? "space" : "no space";

    $_ = "\xA0";
    print /\s/ ? "space" : "no space";

    $_ = "\xA0\x{2660}";
    print /^\s/ ? "space" : "no space";
'
space
space
no space
space