cam: options: Add public method to invalidate options

Extend OptionsBase<T> with a public invalidate() method. This allows for
further examination of the options and if found unsuitable be
invalidated. The intended user for this new interface are subclasses of
KeyValueParser.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/cam/options.cpp

@@ -64,6 +64,12 @@ const OptionValue &OptionsBase<T>::operator[](const T &opt) const
 	return values_.find(opt)->second;
 }
 
+template<typename T>
+void OptionsBase<T>::invalidate()
+{
+	valid_ = false;
+}
+
 template<typename T>
 bool OptionsBase<T>::parseValue(const T &opt, const Option &option,
 				const char *optarg)

src/cam/options.h

@@ -54,6 +54,8 @@ public:
 	bool isSet(const T &opt) const;
 	const OptionValue &operator[](const T &opt) const;
 
+	void invalidate();
+
 private:
 	friend class KeyValueParser;
 	friend class OptionsParser;