3 * ${class}${atomicname}() - atomic compare and exchange with ${desc_order} ordering
4 * @v: pointer to ${atomic}_t
5 * @old: pointer to ${int} value to compare with
6 * @new: ${int} value to assign
8 * If (@v == @old), atomically updates @v to @new with ${desc_order} ordering.
9 * Otherwise, @v is not modified, @old is updated to the current value of @v,
10 * and relaxed ordering is provided.
14 * Return: @true if the exchange occured, @false otherwise.