[v2,4/5] libcamera: controls: Implement `swap()`
diff mbox series

Message ID 20250421153556.171192-5-barnabas.pocze@ideasonboard.com
State New
Headers show
Series
  • libcamera: controls: Move constructor/assignment + swap
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Commit Message

Barnabás Pőcze April 21, 2025, 3:35 p.m. UTC 
Implement both free and member function `swap()` for `ControlValue`.
The general `std::swap()` swaps two values by combining a move construction
and two move assignments, but for `ControlValue` a simpler implementation
can be provided by just swapping the members.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
---
 include/libcamera/controls.h | 19 +++++++++++++++++++
 src/libcamera/controls.cpp   | 15 +++++++++++++++
 2 files changed, 34 insertions(+)

Patch
diff mbox series 

diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index 866d667c4..62ee5ebd6 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -259,6 +259,25 @@  public:
 	void reserve(ControlType type, bool isArray = false,
 		     std::size_t numElements = 1);
 
+	void swap(ControlValue &other) noexcept
+	{
+		/* `type_` is a bit field, so `std::swap()` cannot be used. */
+		{
+			auto tmp = type_;
+			type_ = other.type_;
+			other.type_ = tmp;
+		}
+
+		std::swap(isArray_, other.isArray_);
+		std::swap(numElements_, other.numElements_);
+		std::swap(storage_, other.storage_);
+	}
+
+	friend void swap(ControlValue &a, ControlValue &b) noexcept
+	{
+		a.swap(b);
+	}
+
 private:
 	ControlType type_ : 8;
 	bool isArray_;
diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 135e87613..ae54f8c77 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -412,6 +412,21 @@  void ControlValue::reserve(ControlType type, bool isArray, std::size_t numElemen
 		storage_.external = new uint8_t[newSize];
 }
 
+/**
+ * \fn ControlValue::swap(ControlValue &other) noexcept
+ * \brief Swap two control values
+ *
+ * This function swaps the contained value of \a this with that of \a other.
+ */
+
+/**
+ * \fn ControlValue::swap(ControlValue &a, ControlValue &b) noexcept
+ * \brief Swap two control values
+ *
+ * This function swaps the contained value of \a a with that of \a b.
+ * \sa ControlValue::swap()
+ */
+
 /**
  * \class ControlId
  * \brief Control static metadata