Memset an Array to -1

[rhouli]

I want to use memset to set an array of length framenum. I know how to do it for 0

memset(arrayname, 0, framenum*sizeof(int));,

but im not quite sure how to do it for -1. Any help would be greatly appreciated, thanks.

[Athar]

You don't use memset in C++, but rather std::fill or std::fill_n (defined in <algorithm>).

fill_n(arrayname, framenum, -1);

memset is unsuitable for that, because it sets each byte to a certain value, not each array element.