'Should std::list be deprecated?
According to Bjarne Stroustrup's slides from his Going Native 2012 keynote, insertion and deletion in a std::list are terribly inefficient on modern hardware:
Vector beats list massively for insertion and deletion
If this is indeed true, what use cases are left for std::list? Shouldn't it be deprecated then?
Solution 1:[1]
Whether a vector outperforms a list or not also depends on the type of the elements. For example, for int elements vector is indeed very fast as most of the data fits inside the CPU cache and SIMD instructions can be used for the data copying. So the O(n) complexity of vector doesn't have much impact.
But what about larger data types, where copying doesn't translate to a stream operation, and instead data must be fetched from all over the place? Also, what about hardware that doesn't have large CPU caches and possibly also lacks SIMD instructions? C++ is used on much more than just modern desktop and workstation machines. Deprecating std::list is out of the question.
What Stroustrup is saying in that presentation is that before you pick std::list for your data, you should make sure that it's the right choice for your particular situation. In other words, benchmark and profile. It definitely doesn't say you should always pick std::vector.
Solution 2:[2]
No, and especially not based on one particular graph. There are instances where list will perform better than vector. See: http://www.baptiste-wicht.com/2012/12/cpp-benchmark-vector-list-deque/
And that's ignoring the non-performance differences, as others have mentioned.
Bjarne's point in that talk wasn't that you shouldn't use list. It was that people make too many assumptions about list's performance that often turn out to be wrong. He was simply justifying the stance that vector should always be your default go-to container type unless you actually find a need for the performance or other semantic characteristics of lists.
Solution 3:[3]
std::list is a deque, it has push_front() and pop_front(). It still has a niche role as such, though it may not be the best choice for a deque.
std::list does not reallocate memory, while std::vector may. Sometimes you don't want an item to move in memory (e.g. a stackful coroutine).
Linked lists are related to tree data structures. Both contain links. If we deprecate std::list, then what about tree-based containers?
Solution 4:[4]
Of course not. std::list is a different data structure. Comparing different data structure is good indication of its properties, advantages or disadvantages. But each data structure has its advantage.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 | Nikos C. |
| Solution 2 | |
| Solution 3 | |
| Solution 4 | dchhetri |