libcamera: controls: Drop ControlList::contains()

The ControlList::contains(const ControlId &id) function isn't used, as
it has been replaced by usage of the get() function. Document get as
being the preferred way to check for the presence of a control in a
ControlList, and drop the contains() function.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>

include/libcamera/controls.h

@@ -370,7 +370,6 @@ public:
 	void clear() { controls_.clear(); }
 	void merge(const ControlList &source);
 
-	bool contains(const ControlId &id) const;
 	bool contains(unsigned int id) const;
 
 	template<typename T>

src/libcamera/controls.cpp

@@ -931,17 +931,6 @@ void ControlList::merge(const ControlList &source)
 	}
 }
 
-/**
- * \brief Check if the list contains a control with the specified \a id
- * \param[in] id The control ID
- *
- * \return True if the list contains a matching control, false otherwise
- */
-bool ControlList::contains(const ControlId &id) const
-{
-	return controls_.find(id.id()) != controls_.end();
-}
-
 /**
  * \brief Check if the list contains a control with the specified \a id
  * \param[in] id The control numerical ID
@@ -958,6 +947,10 @@ bool ControlList::contains(unsigned int id) const
  * \brief Get the value of control \a ctrl
  * \param[in] ctrl The control
  *
+ * Beside getting the value of a control, this function can also be used to
+ * check if a control is present in the ControlList by converting the returned
+ * std::optional<T> to bool (or calling its has_value() function).
+ *
  * \return A std::optional<T> containing the control value, or std::nullopt if
  * the control \a ctrl is not present in the list
  */