If you iterate on an std container with this elegant formula:
for (auto& item: queue) {}
It will be using queue's begin and end functions.
Is there a way to use cbegin and cend without modifying the queue's source?
I tried with
for (const auto& item: queue) {}
But if begin or end is missing, it doesn't compile.
You want for (auto& item : std::as_const(queue)) {}. It still calls begin() but it’s const so it picks the const overload.
Is there a way to use cbegin and cend without modifying the queue's source?
In C++20, you can use queue.cbegin() and queue.cend() to construct a ranges::subrange:
#include <ranges>
for (auto& item: std::ranges::subrange(queue.cbegin(), queue.cend())) {}