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Is there any way to do a range-based for loop of part of a vector? For instance, I'd like to iterate over the first 5 elements of the vector:

for(auto& elem : my_vector[0:5]) { // Syntax obviously doesn't exist do_stuff(elem); }

I could write my own container as specified in How to make my custom type to work with "range-based for loops"? but I'm hoping that there is an easier way in boost or some related library.

C++20 appears to include "ranges", but is there anything similar before 20?

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The de facto standard (library) for this is range-v3 — here's how it looks:

for (auto& elem : ranges::view::slice(my_vector, 0, 5)) { ... } // or for (auto& elem : ranges::view::take(my_vector, 5)) { ... }

If you need range support in C++03, Boost.Range is an alternative, though its implementation is rather rudimentary in comparison.

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hm.. so this is not yet standard? This is experimental code isn't it?
No, not yet; but C++20 adds std::span<> which will allow this (but only for contiguous ranges like std::vector<>), and hopefully ranges as well (though not likely the views that are used here).

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