Pointer To Functions = Seg Fault
My problem is, when i call int (*comp)(...) it seg faults on me. I haven't used pointers to functions all that much, and ecspecially not when the target function is a class member - even more so, a template.
Since you're gonna look at my code anyway and if you have extra time:
1. Most importantly, how do i fix the seg fault?
2. Does this look like i'm on the right track?
3. How do i initialize the first 3 variables in my code? (i want to make the private, static, const members)
4. Do you know where i can get some data to test this with? (perhaps a flat file with a couple thousand records)
btw, i know i'll need some destructors
Code:
#ifndef BTREE_H
#define BTREE_H
//work around - need to fix this (seems to be soemthing about it being a template)
const short comp_less = -1;
const short comp_geater = +1;
const short comp_equal = 0;
template<typename _T = int>
class BTree
{
typedef int key_type;
public:
BTree(void);
BTree(const BTree &, const void * = NULL);
BTree(const _T &, const void * = NULL);
key_type insert(const _T &);
private:
_T data;
key_type key;
BTree * right;
BTree * left;
int (*comp)(const _T &, const _T &);
static inline int compare(const _T &, const _T &);
static int __defaultCompare(const _T &, const _T &);
};
template<typename _T>
BTree<_T>::BTree(const _T &srcNode, const void *compareFunction)
{
if(!compareFunction)
comp = BTree<_T>::__defaultCompare;
data = srcNode;
right = left = NULL;
}
template<typename _T>
BTree<_T>::key_type BTree<_T>::insert(const _T &srcNode)
{
BTree *side = NULL;
//SEGFAULT ON CALL TO COMP
// FROM DECLARATION int (*comp)(const _T &, const _T &);
// FROM CONSTRUCTOR: comp = __defaultCompare;
// FROM DECLARATION static int __defaultCompare(const _T &, const _T &);
if(comp(srcNode, data) == comp_less)
side = left;
else
side = right;
//following commented out to find seg fault
/*if(!side)
side = new BTree(srcNode, comp);
else
side->insert(srcNode);*/
return 0;
}
template<typename _T>
int BTree<_T>::__defaultCompare(const _T &a, const _T &b)
{
if(a > b)
return +1;
else if(a < b)
return -1;
else
return 0;
return 0;
}
#endif
