Apply/remove bitmask depending on condition

Question

I would like to simplify the following expression (block is an integer, either 0 or 1):

if (block)
    opts = opts & ~O_NONBLOCK;
else
    opts = opts | O_NONBLOCK;

This is what I've come up with:

opts = block ? opts & ~O_NONBLOCK : opts | O_NONBLOCK;

I'm sure, however, that there's a much clever way to do that.

Answer 1

How about this?

opts = (opts & ~O_NONBLOCK) | (!block * O_NONBLOCK);

I do prefer the explicitness of your first option over this somewhat cryptic solution, though.