what's the bahaviro of pop_back for an empty vector?

[Andy]

Hi,

I did not find documentation on this. I try the following naive
program,

#include <vector>
#include <iostream>

using namespace std;

int main()
{
vector<int> myvec;

cout <<"first pop_back \n";
myvec.pop_back();

cout <<"second pop_back \n";
myvec.pop_back();

return 0;
}

Comipled with gcc-4.0, it just print the strings, then stay for a while
and terminated.

Any insights here?

Thanks,

Andy

 

[Victor Bazarov]

I did not find documentation on this. I try the following naive
program,

#include <vector>
#include <iostream>

using namespace std;

int main()
{
vector<int> myvec;

cout <<"first pop_back \n";
myvec.pop_back();

cout <<"second pop_back \n";
myvec.pop_back();

return 0;
}

Comipled with gcc-4.0, it just print the strings, then stay for a while
and terminated.

Any insights here?

Undefined behaviour. std::vector:op_back() is equivalent to calling
erase(--end()); which when the vector is empty causes the call to 'erase'
with an invalid iterator value.

V

 

[Andre Kostur]

Hi,

I did not find documentation on this. I try the following naive
program,

#include <vector>
#include <iostream>

using namespace std;

int main()
{
vector<int> myvec;

cout <<"first pop_back \n";
myvec.pop_back();

cout <<"second pop_back \n";
myvec.pop_back();

return 0;
}

Comipled with gcc-4.0, it just print the strings, then stay for a while
and terminated.

Any insights here?

Undefined behaviour. Anything can happen.