Re: Debug version works but release crashes by pj_hern
pj_hern
Tue Oct 24 06:12:40 CDT 2006
Arno Kromke wrote:
> Hi,
>
> my console application works well if debug settings are used. Even if I
> build a release version and run it in the IDE everything is fine. If I
> execute the release version of the file, however, it crashes.
>
> If I trace the error using the debugger, it marks the following lines:
>
> ...
> struct Value
> {
> int var;
> int mv;
> };
No constructor provided, how are Value's members initialized?
You have to be organized when you code, the following lines are where,
in main? nobody knows.
> ...
> vector<Value>::iterator iter_test;
> vector<Value>::iterator iter_cur;
What vector type are you using, a std::vector? If so, the above should
be written like so:
// iterator type
typedef std::vector<Value>::iterator ValueIter;
// instances of that type, initialized to the their beginning
ValueIter iter_cur = vCurVar.begin();
ValueIter iter_test = vTestVar.begin();
> ...
> vector<Value> vTestVar;
> vector<Value> vCurVar;
your vectors are empty !!!
>
> iter_cur = vCurVar.begin();
> iter_test = vTestVar.begin();
both iterators are pointing to an empty container.
> ...
> // this section of the code tests if
> // vector A (vTestVar) is equal to vector B (vCurVar)
> if ((*iter_test).var == (*iter_cur).var) // same?
undefined behaviour. Your containers are empty.
> {
> for(; iter_cur != vCurVar.end(); ++iter_cur)
> {
> iter_test = vTestVar.begin();
> // test if (*iter_cur).mv is member in iter_test
> while ( ((*iter_test).mv != (*iter_cur).mv) && (iter_test !=
> vTestVar.end()))
> ++iter_test;
> ...
>
> Any suggestion why it crashes? Why is it running with debug settings?
>
> Greetings,
>
> Arno
Try:
#include <iostream>
#include <string>
#include <vector>
struct Value
{
int var;
Value(int n) : var(n) { }
};
int main()
{
std::vector<Value> vtest;
vtest.push_back(0); // look at the ctor above, var = 0
vtest.push_back(1);
vtest.push_back(2);
// builds a vector of 3 elements, all with var = 2
std::vector<Value> vcur(3, 2);
typedef std::vector<Value>::iterator ValueIter; // a new type
// instances of that type, both set
// to the beginning of their respective containers
ValueIter iter_test = vtest.begin();
ValueIter iter_cur = vcur.begin();
size_t count(0);
for(iter_test; iter_test != vtest.end(); ++iter_test, ++count)
{
std::cout << "vtest[" << count << "] = ";
std::cout << (*iter_test).var << "\t";
std::cout << "vcur[" << count << "] = ";
std::cout << (*iter_cur).var << "\t";
std::string result =
((*iter_test).var == (*iter_cur).var) ? "true" : "false";
std::cout << "equality: " << result;
std::cout << std::endl;
}
return 0;
}
/*
vtest[0] = 0 vcur[0] = 2 equality: false
vtest[1] = 1 vcur[1] = 2 equality: false
vtest[2] = 2 vcur[2] = 2 equality: true
*/