parseNumeric

 //Numeric.RPL_LOGGEDIN
	import std.range : only, takeNone;
	{
		immutable logon = parseNumeric!(Numeric.RPL_LOGGEDIN)(only("test", "someone!someIdent@example.net", "some_account", "Well hello there"));
		assert(logon.get.mask.nickname == "someone");
		assert(logon.get.mask.ident == "someIdent");
		assert(logon.get.mask.host == "example.net");
		assert(logon.get.account == "some_account");
	}
	{
		immutable logon = parseNumeric!(Numeric.RPL_LOGGEDIN)(takeNone(only("")));
		assert(logon.isNull);
	}
	{
		immutable logon = parseNumeric!(Numeric.RPL_LOGGEDIN)(only("test"));
		assert(logon.isNull);
	}
	{
		immutable logon = parseNumeric!(Numeric.RPL_LOGGEDIN)(only("test", "someone!someIdent@example.net"));
		assert(logon.isNull);
	}