Will std::vectors inside another vector reallocate when the first vector reallocates?

Question

I have a vector std::vector> m_contactPairs;

If I call m_contactPairs.push_back() or any other function t

Answer 1

In C++03, a std::vector reallocation will copy ("deep copy") each element. That means for your situation, each vector would be copied.

In C++11 or later, a std::vector reallocation will move each element only if the elements have a move constructor that is noexcept.

Visual Studio 2010 lacks noexcept support, so you would still get a deep copy.