X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fcontainer-wrapper.hpp;h=25385fc43837961ec4301dd9f7254f0b89ccc3b6;hb=HEAD;hp=09097e9358855977837eca2efd86f689f872ea29;hpb=b17ed2ad7083d1b0bf45fe3e1bfc4e4ad787aaf3;p=lttng-tools.git

diff --git a/src/common/container-wrapper.hpp b/src/common/container-wrapper.hpp
index 09097e935..25385fc43 100644
--- a/src/common/container-wrapper.hpp
+++ b/src/common/container-wrapper.hpp
@@ -8,6 +8,8 @@
 #ifndef LTTNG_CONTAINER_WRAPPER_H
 #define LTTNG_CONTAINER_WRAPPER_H
 
+#include <common/exception.hpp>
+#include <common/format.hpp>
 #include <common/macros.hpp>
 
 #include <cstddef>
@@ -24,10 +26,10 @@ namespace utils {
  */
 template <typename ContainerType, typename ElementType, typename ContainerOperations>
 class random_access_container_wrapper {
+	template <typename IteratorContainerType, typename IteratorElementType>
 	class _iterator : public std::iterator<std::random_access_iterator_tag, std::size_t> {
 	public:
-		explicit _iterator(const random_access_container_wrapper& container,
-				   std::size_t start_index = 0) :
+		explicit _iterator(IteratorContainerType& container, std::size_t start_index = 0) :
 			_container(container), _index(start_index)
 		{
 		}
@@ -58,6 +60,11 @@ class random_access_container_wrapper {
 			return *this;
 		}
 
+		ptrdiff_t operator-(const _iterator& other) const
+		{
+			return _index - other._index;
+		}
+
 		bool operator==(const _iterator& other) const noexcept
 		{
 			return _index == other._index;
@@ -68,23 +75,25 @@ class random_access_container_wrapper {
 			return !(*this == other);
 		}
 
-		typename std::conditional<std::is_pointer<ElementType>::value,
-					  ElementType,
-					  ElementType&>::type
-		operator*() const noexcept
+		typename std::conditional<std::is_pointer<IteratorElementType>::value,
+					  IteratorElementType,
+					  IteratorElementType&>::type
+		operator*() const
 		{
 			return _container[_index];
 		}
 
 	private:
-		const random_access_container_wrapper& _container;
+		IteratorContainerType& _container;
 		std::size_t _index;
 	};
 
-	using iterator = _iterator;
+	using iterator = _iterator<random_access_container_wrapper, ElementType>;
+	using const_iterator = _iterator<const random_access_container_wrapper, const ElementType>;
 
 public:
-	explicit random_access_container_wrapper(ContainerType container) : _container{ container }
+	explicit random_access_container_wrapper(ContainerType container) :
+		_container{ std::move(container) }
 	{
 	}
 
@@ -93,21 +102,50 @@ public:
 		return iterator(*this);
 	}
 
-	iterator end() noexcept
+	iterator end()
+	{
+		return iterator(*this, size());
+	}
+
+	const_iterator begin() const noexcept
 	{
-		return iterator(*this, ContainerOperations::size(_container));
+		return const_iterator(*this);
 	}
 
-	std::size_t size() const noexcept
+	const_iterator end() const
+	{
+		return const_iterator(*this, size());
+	}
+
+	std::size_t size() const
 	{
 		return ContainerOperations::size(_container);
 	}
 
+	bool empty() const
+	{
+		return size() == 0;
+	}
+
 	typename std::conditional<std::is_pointer<ElementType>::value, ElementType, ElementType&>::type
 	operator[](std::size_t index)
 	{
-		LTTNG_ASSERT(index < ContainerOperations::size(_container));
-		return ContainerOperations::get(_container, index);
+		/*
+		 * To share code between the const and mutable versions of this operator, 'this'
+		 * is casted to a const reference. A const_cast then ensures that a mutable
+		 * reference (or pointer) is returned.
+		 *
+		 * We typically avoid const_cast, but this is safe: if the user is calling the
+		 * mutable version of this operator, it had a mutable object anyhow.
+		 *
+		 * For more information, see Item 3 of Effective C++.
+		 */
+		const auto& const_this = static_cast<const random_access_container_wrapper&>(*this);
+
+		/* NOLINTNEXTLINE(cppcoreguidelines-pro-type-const-cast) */
+		return const_cast<typename std::conditional<std::is_pointer<ElementType>::value,
+							    ElementType,
+							    ElementType&>::type>(const_this[index]);
 	}
 
 	typename std::conditional<std::is_pointer<ElementType>::value,
@@ -115,11 +153,17 @@ public:
 				  const ElementType&>::type
 	operator[](std::size_t index) const
 	{
-		LTTNG_ASSERT(index < ContainerOperations::size(_container));
+		if (index >= ContainerOperations::size(_container)) {
+			throw std::invalid_argument(lttng::format(
+				"Out of bound access through random_access_container_wrapper: index={}, size={}",
+				index,
+				size()));
+		}
+
 		return ContainerOperations::get(_container, index);
 	}
 
-private:
+protected:
 	ContainerType _container;
 };
 } /* namespace utils */