memcpy src & dst same

[clu]

If the source and destination pointers happen to be the same during a
memcpy(), is that going to cause undefined behavior?

int *src = &myarr[0];
int *dst = &myarr[0];

memcpy( dst, src, sizeof(myarr) );

 

[Peter Nilsson]

If the source and destination pointers happen to be the same during a
memcpy(), is that going to cause undefined behavior?

int *src = &myarr[0];
int *dst = &myarr[0];

memcpy( dst, src, sizeof(myarr) );

Yes. 7.21.2.1p2 "... If copying takes place between objects that
overlap, the behavior is undefined."

 

[Richard Bos]

If the source and destination pointers happen to be the same during a
memcpy(), is that going to cause undefined behavior?

int *src = &myarr[0];
int *dst = &myarr[0];

memcpy( dst, src, sizeof(myarr) );

Yes. If this is a problem, use memmove() instead.

Richard