libcamera: controls: Move ControlValue constructor to controls.h

To avoid defining all specializations of the ControlValue constructor
manually, move the definition of those functions to controls.h and turn
them into a single template function. The default constructor is still
kept in controls.cpp.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/controls.h

@@ -55,9 +55,13 @@ class ControlValue
 {
 public:
 	ControlValue();
-	ControlValue(bool value);
-	ControlValue(int32_t value);
-	ControlValue(int64_t value);
+
+	template<typename T>
+	ControlValue(T value)
+		: type_(details::control_type<std::remove_cv_t<T>>::value)
+	{
+		*reinterpret_cast<T *>(&bool_) = value;
+	}
 
 	ControlType type() const { return type_; }
 	bool isNone() const { return type_ == ControlTypeNone; }

src/libcamera/controls.cpp

@@ -74,31 +74,10 @@ ControlValue::ControlValue()
 }
 
 /**
- * \brief Construct a Boolean ControlValue
- * \param[in] value Boolean value to store
+ * \fn template<typename T> T ControlValue::ControlValue(T value)
+ * \brief Construct a ControlValue of type T
+ * \param[in] value Initial value
  */
-ControlValue::ControlValue(bool value)
-	: type_(ControlTypeBool), bool_(value)
-{
-}
-
-/**
- * \brief Construct an integer ControlValue
- * \param[in] value Integer value to store
- */
-ControlValue::ControlValue(int32_t value)
-	: type_(ControlTypeInteger32), integer32_(value)
-{
-}
-
-/**
- * \brief Construct a 64 bit integer ControlValue
- * \param[in] value Integer value to store
- */
-ControlValue::ControlValue(int64_t value)
-	: type_(ControlTypeInteger64), integer64_(value)
-{
-}
 
 /**
  * \fn ControlValue::type()