Date: 2010may14 Language: C/C++ Keywords: Standard Template Library Q. How do I efficiently copy an STL vector to a STL map? A. There are two "tricks": - Reserve the space in advance (for speed) - Use .first or .second to access the map content Of course, a map holds a key and a value; and a vector does not. So you have to decide what you are copying. The code:

void CopyMapToVector(MYMAP &mymap, MYVECTOR &myvec) { myvec.clear(); // Delete what was in the vector (if anything) // As we mentioned above... reserve the space. Makes it much faster. myvec.reserve(mymap.size()); for (MYMAP::iterator it = mymap.begin(); it != mymap.end(); it++) { // If you want to copy the keys do this: myvec.push_back((*it).first); // Or if you want to copy the values do this: // myvec.push_back((*it).second); } }