в 14:21, 25 мая 2010

2010-05-25T14:21:06Z

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2010-05-25T10:23:58Z

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==bad_alloc standard exception==

<source lang="cpp">
#include <iostream>
#include <exception>
using namespace std;
int main () {
try
{
int* myarray= new int[1000];
}
catch (exception& e)
{
cout << "Standard exception: " << e.what() << endl;
}
return 0;
}

</source>

==delete memory allocate for objects==

<source lang="cpp">
#include <iostream>
#include <stdlib.h>
using namespace std;
class loc
{
int longitude, latitude;
public:
loc(void) {}
loc (int lg, int lt)
{
longitude = lg;
latitude = lt;
}
void show(void)
{
cout << longitude << " ";
cout << latitude << endl;
}
void *operator new(size_t size);
void operator delete(void *p);
void *operator new[](size_t size);
void operator delete[](void *p);
};
void *loc::operator new(size_t size)
{
cout << "In the custom new function." << endl;
return malloc(size);
}
void loc::operator delete(void *p)
{
cout << "In the custom delete function." << endl;
free(p);
}
void *loc::operator new[](size_t size)
{
cout << "In the custom new ARRAY allocator function." << endl;
return malloc(size);
}
void loc::operator delete[](void *p)
{
cout << "Freeing the ARRAY in the custom delete function." << endl;
free(p);
}
int main(void)
{
loc *p1, *p2;
int i;
p1 = new loc(10,20);
if (!p1)
{
cout << "Allocation error\n";
exit(1);
}
p2 = new loc[10];
if (!p2)
{
cout << "Allocation error\n";
exit(1);
}
p1->show();
for(i=0; i<10; i++)
p2[i].show();
delete p1;
delete [] p2;
}

</source>

==Demonstrating new throwing bad_alloc when memory is not allocated==

<source lang="cpp">
#include <iostream>
using std::cout;
using std::endl;
#include <new>
using std::bad_alloc;
int main()
{
double *ptr[ 50 ];

try {
for ( int i = 0; i < 50; i++ ) {
ptr[ i ] = new double[ 5000000 ];
cout << "Allocated 5000000 doubles in ptr[ " << i << " ]\n";
}
}
catch ( bad_alloc exception ) {
cout << "Exception occurred: "
<< exception.what() << endl;
}

return 0;
}

</source>

==Use new operator to allocate memory for object==

<source lang="cpp">
#include <iostream>
#include <stdlib.h>
using namespace std;
class loc
{
int longitude, latitude;
public:
loc(void) {}
loc (int lg, int lt)
{
longitude = lg;
latitude = lt;
}
void show(void)
{
cout << longitude << " ";
cout << latitude << endl;
}
void *operator new(size_t size);
void operator delete(void *p);
};
void *loc::operator new(size_t size)
{
cout << "In the custom new function." << endl;
return malloc(size);
}
void loc::operator delete(void *p)
{
cout << "In the custom delete function." << endl;
free(p);
}
int main(void)
{
loc *p1, *p2;
p1 = new loc(10,20);
if (!p1)
{
cout << "Allocation error\n";
exit(1);
}
p2 = new loc(-10,-20);
if (!p2)
{
cout << "Allocation error\n";
exit(1);
}
p1->show();
p2->show();
delete p1;
delete p2;
exit (0);
}

</source>

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в 14:21, 25 мая 2010

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