memory allocation on struct in c++

memory allocation on struct in c++

My struct is as follow:
typedef struct KeypointSt {
float row, col;
float scale, ori;
unsigned char *descrip; /* Vector of descriptor values */
struct KeypointSt *next;
} *Keypoint;
The following is a part of a code in c. how can I translate it to
c++,considering allocation and de-allocation of heap.
Keypoint k, keys = NULL;
for (i = 0; i < num; i++) {
/* Allocate memory for the keypoint. */
k = (Keypoint) malloc(sizeof(struct KeypointSt));
k->next = keys;
keys = k;
k->descrip = malloc(len);
for (j = 0; j < len; j++) {
k->descrip[j] = (unsigned char) val;
}
}
Thanks.