I only have access to C++03 and I often want to move a vector into a function the way you can do it in C++11. The question how to do it not to confuse the user of the code too much. So my question is how did programmers do it before C++11.
I know that vector can be "moved" using swap function. So here is what I have come up with:
class Foo
{
public:
Foo(std::vector<int>& vec)
{
using std::swap;
swap(vec, m_vec); // "move" vec into member vector
}
private:
std::vector<int> m_vec;
};
// usage:
std::vector<int> v(100, 1337);
Foo foo(v);
// v.empty() == true
The problem with this approach is that its not evident to the user that their vector will be moved into the class Foo. Is there a best practice solution to this kind of problem? Thanks in advance!
Best Answer
You could define a type wrapping a reference, and a function to wrap it, to give something similar to move semantics at the call site. Something along the lines of
Alternatively, Boost has a library to allow move semantics without C++11.