Range-for-loops and std::vector

Question

Why does this code work

std::vector intVector(10);
for(auto& i : intVector)
    std::cout << i;

And this doesn\'t?

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Answer 1

vector is (usually) specialized explicitly to store each bool in a single bit, reducing the storage costs from one byte per value to one byte per eight values. No processor I know of offhand is bit addressable, so it's impossible to store a reference to the values in the vector. You need to use plain auto, not auto& for the iteration value i.