memory management - C++ vector adding elements efficiently -

suppose have following code:

#include <iostream> #include <vector> using namespace std;  class x { public:   int x[1000];   x(int y) { (int = 0; < 1000; i++) x[i] = y; } };  int main() {   vector<x> v;   x x0(0);   x x1(1);   x x2(2);   v.push_back(x0);   v.push_back(x1);   v.push_back(x2);   cout << v[2].x[33] << endl;   return 0; } 

if understand correctly, in code, allocating memory on stack x0, x1 , x2, copying contents onto memory allocated me vector. furthermore, far understand, move semantics can't here because it's not x holding pointer resource located somewhere else.

is possible me directly call constructor on raw memory block allocated me vector? if not, proper way handle situations these?

you need use c++11's emplace_back.

http://en.cppreference.com/w/cpp/container/vector/emplace_back

also, if you're concerned excess copies/moves, try starting v.reserve(3).