Is this the simplest/shortest way to get size in memory of the content of what std::array::data() returns?
arr.size() * sizeof(arr.value_type)
Edit: My question wasn't precise. By "size in memory" I mean size of all elements (themselves) contained in the array so if e.g. they are pointers pointing to structures, I want the size of the pointers alone, not the structures pointed to. I also don't want to include the size of any possible overhead of the std::arr implementation. Just the array elements.
Some people suggested sizeof(arr). This: What is the sizeof std::array<char, N>? begs to disagree. And while it seems to work on my machine I want to know what the standard guarantees.
Since no one has posted anything better than my first guess in question and sizeof(arr) is most likely NOT guaranteed to not include the size of any possible additional std::array's fields I'm choosing this as the accepted answer.
arr.size() * sizeof(arr.value_type)
Should anyone come up with anything better I'd be happy to accept their answer instead.