Memset doesn't fill the whole pointer array c++

Question

I have an array of pixels of 1049088 size, in my computer, and I want to fill it completely. But when I use memset it just gets filled to a point of the array, not the whole block.

I have gone to http://www.cplusplus.com/reference/cstring/memset/ and it says nothing about a maximum size. Also, my variable is size_t (unsigned int) so it should return me an error if I put a higher value than expected, but it's in range.

memset((void*)pixels, BLACK_CLR, w_widthxheight);

The w_widthxheight is a size_t that contains 1049088. The pixels is a COLORREF array with the size of the same variable (w_widthxheight). The BLACK_CLR constant contains 0.

If there's any alternative to memset, because I've read that it's unefficient somewhere (but works fine the first x values of the array) it would be good too.

Answer 1

You are giving the size in elements, but memset expects the size to be in bytes. So this should fix it:

memset((void*)pixels, BLACK_CLR, w_widthxheight * sizeof( COLORREF ) );