Alternatives to std::reverse to reserve all elements in a vector?

Question

std::vector<int> temp;
temp.insert(temp.begin(), points1.begin(), points1.end());
points1.clear();
std::vector<int> points1(temp.end(), temp.begin());
temp.clear();

I tried this but I've got an exception connects to memory allocation.

Answer 1

Use std::rbegin to iterate in the reverse order.

If you try points1(temp.end(), temp.begin()); , it starts from and illegal iterator (the end...).

Also, you're declaring points1 a second time in the code you provided

Answer 2

You can do this with one line of code. Construct a temporary vector using reverse iterators and then swap its contents back into the original vector.

// original vector
std::vector<int> points1;

// create temporary using reverse iterators and swap with original vector
std::vector<int>(points1.rbegin(), points1.rend()).swap(points1);

// unnamed temporary is destroyed automatically

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