Dynamic memory allocation problem

I am trying to write a function to do dynamic memory allocation with a try catch block, so that I don't have to manually write a try catch block each time I want to allocate memory for an array. The code bellow is supposed to do that, but it outputs:

Allocated memory for small array
Segmentation fault

So apparently the function creates a copy of the array and allocates memory for the copy, but not for the original array. How do I fix this? Thanks in advance.

# include <iostream>
# include <fstream>
# include <string>
# include <cstring>
# include <sstream>
# include <time.h>
# include <iomanip>
# include <vector>

using namespace std;

template <class T>
bool SafeArrayAlloc(T *array, int Size)
{
try
{
array=new T[Size];
}
catch(bad_alloc&)
{
return false;
}
return true;
}

int main(int argc, char * argv[])
{
int big, small;
int *big_array, *small_array;

big=3000000000;
small=10;

if (!SafeArrayAlloc(&small_array, small))
{
cout <<"Unable to allocate memory for small array"<<endl;
}
else
{
cout <<"Allocated memory for small array"<<endl;
for (int i=0;i<small;i++) small_array[i]=0;
for (int i=0;i<small;i++) small_array[i]=i;
for (int i=0;i<small;i++) cout <<small_array[i]<<endl;
}

if (!SafeArrayAlloc(&big_array, big))
{
cout <<"Unable to allocate memory for big array"<<endl;
}
else
{
cout <<"Allocated memory for big array"<<endl;
for (int i=0;i<big;i++) big_array[i]=0;
for (int i=0;i<big;i++) big_array[i]=i;
for (int i=0;i<big;i++) cout <<big_array[i]<<endl;
}

return EXIT_SUCCESS;
}

bool SafeArrayAlloc(T*& array, int Size);

I am guessing that will fix your problem without looking that much. Also there is no need to create this function to implement a nothrow new.. just use
int* I = new (nothrow) int [array size] ();
http://www.cplusplus.com/reference/std/new/nothrow/

Thanks. It worked. I tried bool SafeArrayAlloc(T&* array, int Size) previously but it did not work. You are probably right that this function is not very useful, but I also wanted to write a function for multidimensional array allocation and I can't do that without getting this function to work. Thanks again.

Quote:

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Originally Posted by BrainInVat

Thanks. It worked. I tried bool SafeArrayAlloc(T&* array, int Size) previously but it did not work. You are probably right that this function is not very useful,

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The real question is why did you need to write this when std::vector is available?

You even included <vector> in your code, but for some unexplained reason, you need to write this instead. :confused:

Regards,

Paul McKenzie

Quote:

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Originally Posted by BrainInVat

I also wanted to write a function for multidimensional array allocation and I can't do that without getting this function to work. Thanks again.

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You should consider whether boost::multi_array solves your problem.