HP Integrity NonStop H-Series - Manual (Page 232)

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©Copyright 1996 Rogue Wave Software
Example Program
This program illustrates the use of auto_ptr to ensure that pointers held in a vector are deleted
when they are removed. Often, we might want to hold pointers to strings, since the strings
themselves may be quite large and we'll be copying them when we put them into the vector.
Particularly in contrast to a string, an auto_ptr is quite small: hardly bigger than a pointer. (Note
that the program runs as is because the vector includes memory.)
Obtaining the Sample Program.
#include
#include
#include
int main()
{
{
// First the wrong way
vector v;
v.insert(v.begin(), new string("Florence"));
v.insert(v.begin(), new string("Milan"));
v.insert(v.begin(), new string("Venice"));
// Now remove the first element
v.erase(v.begin());
// Whoops, memory leak
// string("Venice") was removed, but not deleted
// We were supposed to handle that ourselves
}
{
// Now the right way
vector > v;
v.insert(v.begin(),
auto_ptr(new string("Florence")));
v.insert(v.begin(), auto_ptr(new string("Milan")));