How do I avoid iterator invalidation with std::multiset?

Iterator invalidation is a common concern when using containers from the C++ Standard Library, including `std::multiset`. This container allows multiple elements with equivalent keys but can invalidate iterators under certain conditions. To avoid iterator invalidation with `std::multiset`, consider the following best practices:

Use Stable Iterators: Always ensure that your iterations do not attempt to modify the multiset while iterating through it.
Store Iterators: Instead of directly modifying elements, store iterators to the elements you need to work with, and modify the multiset after you finish iterating.
Use Functions to Modify: Consider using functions to encapsulate modifications to the multiset that operate on a snapshot of the iterators.

Here is an example of how to safely work with `std::multiset` without invalidating iterators:


    #include <set>
    #include <iostream>

    int main() {
        std::multiset ms = {1, 2, 2, 3, 4, 5};

        // Store iterators before modifying the multiset
        std::multiset::iterator it = ms.find(2);
        
        // Safely removing elements after storing iterators
        while (it != ms.end()) {
            // This is safe because it doesn't invalidate the previous iterator
            it = ms.erase(it); // Erase returns the next iterator
        }

        // Output the contents of the multiset
        for (const auto& value : ms) {
            std::cout << value << " ";
        }
        return 0;
    }

How do I avoid iterator invalidation with std::multiset?

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How do I avoid iterator invalidation with std::multiset?

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