libcamera: controls: Make ControlValue get/set accessors template methods

The ControlValue get accessors are implemented with functions of
different names, whlie the set accessors use polymorphism to support
different control types. This isn't very consistent and intuitive. Make
the API clearer by using template methods. This will also have the added
advantage that support for the new types will only require adding
template specialisations, without adding new methods.

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

1 files changed, 39 insertions, 48 deletions

diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 9960a30d..88aab88d 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -90,77 +90,68 @@ ControlValue::ControlValue(int64_t value)
  */
 
 /**
- * \brief Set the value with a boolean
- * \param[in] value Boolean value to store
+ * \fn template<typename T> const T &ControlValue::get() const
+ * \brief Get the control value
+ *
+ * The control value type shall match the type T, otherwise the behaviour is
+ * undefined.
+ *
+ * \return The control value
  */
-void ControlValue::set(bool value)
-{
-	type_ = ControlTypeBool;
-	bool_ = value;
-}
 
 /**
- * \brief Set the value with an integer
- * \param[in] value Integer value to store
+ * \fn template<typename T> void ControlValue::set(const T &value)
+ * \brief Set the control value to \a value
+ * \param[in] value The control value
  */
-void ControlValue::set(int value)
-{
-	type_ = ControlTypeInteger;
-	integer_ = value;
-}
 
-/**
- * \brief Set the value with a 64 bit integer
- * \param[in] value 64 bit integer value to store
- */
-void ControlValue::set(int64_t value)
-{
-	type_ = ControlTypeInteger64;
-	integer64_ = value;
-}
-
-/**
- * \brief Get the boolean value
- *
- * The value type must be Boolean.
- *
- * \return The boolean value
- */
-bool ControlValue::getBool() const
+#ifndef __DOXYGEN__
+template<>
+const bool &ControlValue::get<bool>() const
 {
 	ASSERT(type_ == ControlTypeBool);
 
 	return bool_;
 }
 
-/**
- * \brief Get the integer value
- *
- * The value type must be Integer or Integer64.
- *
- * \return The integer value
- */
-int ControlValue::getInt() const
+template<>
+const int &ControlValue::get<int>() const
 {
 	ASSERT(type_ == ControlTypeInteger || type_ == ControlTypeInteger64);
 
 	return integer_;
 }
 
-/**
- * \brief Get the 64-bit integer value
- *
- * The value type must be Integer or Integer64.
- *
- * \return The 64-bit integer value
- */
-int64_t ControlValue::getInt64() const
+template<>
+const int64_t &ControlValue::get<int64_t>() const
 {
 	ASSERT(type_ == ControlTypeInteger || type_ == ControlTypeInteger64);
 
 	return integer64_;
 }
 
+template<>
+void ControlValue::set<bool>(const bool &value)
+{
+	type_ = ControlTypeBool;
+	bool_ = value;
+}
+
+template<>
+void ControlValue::set<int>(const int &value)
+{
+	type_ = ControlTypeInteger;
+	integer_ = value;
+}
+
+template<>
+void ControlValue::set<int64_t>(const int64_t &value)
+{
+	type_ = ControlTypeInteger64;
+	integer64_ = value;
+}
+#endif /* __DOXYGEN__ */
+
 /**
  * \brief Assemble and return a string describing the value
  * \return A string describing the ControlValue