libcamera: Use helper variable template for type traits

C++17 introduces helper variable templates for type traits, allowing
shortening std::is_foo<T>::value to std::is_foo_v<T>. Use them through
the code base.

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

5 files changed, 34 insertions, 34 deletions

diff --git a/include/libcamera/bound_method.h b/include/libcamera/bound_method.h
index 95a95653..feac51da 100644
--- a/include/libcamera/bound_method.h
+++ b/include/libcamera/bound_method.h
@@ -63,7 +63,7 @@ public:
 	}
 	virtual ~BoundMethodBase() = default;
 
-	template<typename T, typename std::enable_if_t<!std::is_same<Object, T>::value> * = nullptr>
+	template<typename T, typename std::enable_if_t<!std::is_same_v<Object, T>> * = nullptr>
 	bool match(T *obj) { return obj == obj_; }
 	bool match(Object *object) { return object == object_; }
 
diff --git a/include/libcamera/controls.h b/include/libcamera/controls.h
index 3b7f3347..dc549a92 100644
--- a/include/libcamera/controls.h
+++ b/include/libcamera/controls.h
@@ -98,7 +98,7 @@ public:
 #ifndef __DOXYGEN__
 	template<typename T, typename std::enable_if_t<!details::is_span<T>::value &&
 						       details::control_type<T>::value &&
-						       !std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       !std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 	ControlValue(const T &value)
 		: type_(ControlTypeNone), numElements_(0)
@@ -108,7 +108,7 @@ public:
 	}
 
 	template<typename T, typename std::enable_if_t<details::is_span<T>::value ||
-						       std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 #else
 	template<typename T>
@@ -142,7 +142,7 @@ public:
 
 #ifndef __DOXYGEN__
 	template<typename T, typename std::enable_if_t<!details::is_span<T>::value &&
-						       !std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       !std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 	T get() const
 	{
@@ -153,7 +153,7 @@ public:
 	}
 
 	template<typename T, typename std::enable_if_t<details::is_span<T>::value ||
-						       std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 #else
 	template<typename T>
@@ -170,7 +170,7 @@ public:
 
 #ifndef __DOXYGEN__
 	template<typename T, typename std::enable_if_t<!details::is_span<T>::value &&
-						       !std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       !std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 	void set(const T &value)
 	{
@@ -179,7 +179,7 @@ public:
 	}
 
 	template<typename T, typename std::enable_if_t<details::is_span<T>::value ||
-						       std::is_same<std::string, std::remove_cv_t<T>>::value,
+						       std::is_same_v<std::string, std::remove_cv_t<T>>,
 						       std::nullptr_t> = nullptr>
 #else
 	template<typename T>
diff --git a/include/libcamera/object.h b/include/libcamera/object.h
index a1882f05..423208db 100644
--- a/include/libcamera/object.h
+++ b/include/libcamera/object.h
@@ -32,7 +32,7 @@ public:
 	void postMessage(std::unique_ptr<Message> msg);
 
 	template<typename T, typename R, typename... FuncArgs, typename... Args,
-		 typename std::enable_if_t<std::is_base_of<Object, T>::value> * = nullptr>
+		 typename std::enable_if_t<std::is_base_of_v<Object, T>> * = nullptr>
 	R invokeMethod(R (T::*func)(FuncArgs...), ConnectionType type,
 		       Args... args)
 	{
diff --git a/include/libcamera/signal.h b/include/libcamera/signal.h
index 5bcd7a77..46d917d5 100644
--- a/include/libcamera/signal.h
+++ b/include/libcamera/signal.h
@@ -44,7 +44,7 @@ public:
 	}
 
 #ifndef __DOXYGEN__
-	template<typename T, typename R, typename std::enable_if_t<std::is_base_of<Object, T>::value> * = nullptr>
+	template<typename T, typename R, typename std::enable_if_t<std::is_base_of_v<Object, T>> * = nullptr>
 	void connect(T *obj, R (T::*func)(Args...),
 		     ConnectionType type = ConnectionTypeAuto)
 	{
@@ -52,7 +52,7 @@ public:
 		SignalBase::connect(new BoundMethodMember<T, void, Args...>(obj, object, func, type));
 	}
 
-	template<typename T, typename R, typename std::enable_if_t<!std::is_base_of<Object, T>::value> * = nullptr>
+	template<typename T, typename R, typename std::enable_if_t<!std::is_base_of_v<Object, T>> * = nullptr>
 #else
 	template<typename T, typename R>
 #endif
diff --git a/include/libcamera/span.h b/include/libcamera/span.h
index 91e9f974..d720adb8 100644
--- a/include/libcamera/span.h
+++ b/include/libcamera/span.h
@@ -125,8 +125,8 @@ public:
 
 	template<std::size_t N>
 	constexpr Span(element_type (&arr)[N],
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
+		       std::enable_if_t<std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
+							      element_type (*)[]> &&
 					N == Extent,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(arr)
@@ -135,8 +135,8 @@ public:
 
 	template<std::size_t N>
 	constexpr Span(std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
+		       std::enable_if_t<std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
+							      element_type (*)[]> &&
 					N == Extent,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(arr.data())
@@ -145,8 +145,8 @@ public:
 
 	template<std::size_t N>
 	constexpr Span(const std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value &&
+		       std::enable_if_t<std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
+							      element_type (*)[]> &&
 					N == Extent,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(arr.data())
@@ -157,9 +157,9 @@ public:
 	explicit constexpr Span(Container &cont,
 				std::enable_if_t<!details::is_span<Container>::value &&
 						 !details::is_array<Container>::value &&
-						 !std::is_array<Container>::value &&
-						 std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-								     element_type (*)[]>::value,
+						 !std::is_array_v<Container> &&
+						 std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
+								       element_type (*)[]>,
 						 std::nullptr_t> = nullptr)
 		: data_(utils::data(cont))
 	{
@@ -169,9 +169,9 @@ public:
 	explicit constexpr Span(const Container &cont,
 				std::enable_if_t<!details::is_span<Container>::value &&
 						 !details::is_array<Container>::value &&
-						 !std::is_array<Container>::value &&
-						 std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-								     element_type (*)[]>::value,
+						 !std::is_array_v<Container> &&
+						 std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
+								       element_type (*)[]>,
 						 std::nullptr_t> = nullptr)
 		: data_(utils::data(cont))
 	{
@@ -180,7 +180,7 @@ public:
 
 	template<class U, std::size_t N>
 	explicit constexpr Span(const Span<U, N> &s,
-				std::enable_if_t<std::is_convertible<U (*)[], element_type (*)[]>::value &&
+				std::enable_if_t<std::is_convertible_v<U (*)[], element_type (*)[]> &&
 						 N == Extent,
 						 std::nullptr_t> = nullptr) noexcept
 		: data_(s.data())
@@ -293,8 +293,8 @@ public:
 
 	template<std::size_t N>
 	constexpr Span(element_type (&arr)[N],
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value,
+		       std::enable_if_t<std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
+							      element_type (*)[]>,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(arr), size_(N)
 	{
@@ -302,8 +302,8 @@ public:
 
 	template<std::size_t N>
 	constexpr Span(std::array<value_type, N> &arr,
-		       std::enable_if_t<std::is_convertible<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
-							    element_type (*)[]>::value,
+		       std::enable_if_t<std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(arr))> (*)[],
+							      element_type (*)[]>,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(utils::data(arr)), size_(N)
 	{
@@ -319,9 +319,9 @@ public:
 	constexpr Span(Container &cont,
 		       std::enable_if_t<!details::is_span<Container>::value &&
 					!details::is_array<Container>::value &&
-					!std::is_array<Container>::value &&
-					std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-							    element_type (*)[]>::value,
+					!std::is_array_v<Container> &&
+					std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
+							      element_type (*)[]>,
 					std::nullptr_t> = nullptr)
 		: data_(utils::data(cont)), size_(utils::size(cont))
 	{
@@ -331,9 +331,9 @@ public:
 	constexpr Span(const Container &cont,
 		       std::enable_if_t<!details::is_span<Container>::value &&
 					!details::is_array<Container>::value &&
-					!std::is_array<Container>::value &&
-					std::is_convertible<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
-							    element_type (*)[]>::value,
+					!std::is_array_v<Container> &&
+					std::is_convertible_v<std::remove_pointer_t<decltype(utils::data(cont))> (*)[],
+							      element_type (*)[]>,
 					std::nullptr_t> = nullptr)
 		: data_(utils::data(cont)), size_(utils::size(cont))
 	{
@@ -341,7 +341,7 @@ public:
 
 	template<class U, std::size_t N>
 	constexpr Span(const Span<U, N> &s,
-		       std::enable_if_t<std::is_convertible<U (*)[], element_type (*)[]>::value,
+		       std::enable_if_t<std::is_convertible_v<U (*)[], element_type (*)[]>,
 					std::nullptr_t> = nullptr) noexcept
 		: data_(s.data()), size_(s.size())
 	{