Back to Basics: Iterators in C++ - Nicolai Josuttis - CppCon 2023

C++ iterators allow you to iterate over elements in a container or range, providing a way to access and manipulate data independently of its underlying type.

Key takeaways

Iterators are a fundamental concept in C++ that allow you to iterate over elements in a container.
Iterators can be categorized into different types, including input iterators, output iterators, forward iterators, bidirectional iterators, and random access iterators.
The iterator categories have changed in C++20, with the introduction of a new category called “sentinel” iterators.
Iterators can be used to iterate over elements in a container, and can be used with algorithms to perform operations on the elements.
Iterators can also be used to iterate over elements in a range, which is a sequence of elements that can be iterated over.
The begin() and end() functions are used to get the first and last iterators of a range, respectively.
The ++ operator is used to increment an iterator to the next element in the range.
The -- operator is used to decrement an iterator to the previous element in the range.
The * operator is used to dereference an iterator and access the element it points to.
The -> operator is used to access the elements of a container using an iterator.
Iterators can be used to iterate over elements in a container in a generic way, without knowing the specific type of the container.
Iterators can be used to iterate over elements in a range in a generic way, without knowing the specific type of the range.
The auto keyword can be used to automatically deduce the type of an iterator.
The const keyword can be used to specify that an iterator should not be modified.
The iterator_category type trait can be used to determine the category of an iterator.
The iterator_traits type trait can be used to determine the properties of an iterator.
Iterators can be used to iterate over elements in a container in a way that is independent of the specific type of the container.
Iterators can be used to iterate over elements in a range in a way that is independent of the specific type of the range.
The std::begin() and std::end() functions can be used to get the first and last iterators of a range, respectively.
The std::advance() function can be used to advance an iterator to a specific position in the range.
The std::distance() function can be used to get the distance between two iterators in a range.
The std::next() function can be used to get the next iterator in a range.
The std::prev() function can be used to get the previous iterator in a range.
The std::advance() function can be used to advance an iterator to a specific position in the range.
The std::distance() function can be used to get the distance between two iterators in a range.
The std::next() function can be used to get the next iterator in a range.
The std::prev() function can be used to get the previous iterator in a range.

Back to Basics: Iterators in C++ - Nicolai Josuttis - CppCon 2023

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