c++ - Does resizing an STL vector erase/invalidate its previous contents? -
it doesn't appear (sample program), can sure? // resizing stl vector erase/invalidate it's previous contents? #include <stdio.h> #include <vector> using namespace std ; void print( vector<int>& t ) { for( int = 0 ; < t.size() ; i++ ) printf( "%d ", t[i] ) ; puts(""); } int main() { vector<int> t ; t.resize( 12,9999 ) ; print(t) ; t.resize( 15, 10000 ) ; print(t) ; } resizing stl vector may require reallocating underlying storage. may cause number of elements destroyed , recreated, , all iterators invalidated. accessing invalidated iterator common source of errors when using stl. the contents of each element same, unless copy constructor doesn't work. int main(int argc, char *argv[]) { int data[] = { 1, 2, 3 }; std::vector vec(data, data + 3); // vector contains 1, 2, 3 std::vector::iterator = vec.begin(); cout << *i << endl; // prints 1 int
