[noselasd]

    bool a = someInt & 0x02;

is perfectly fine in C99. 0 converts to false, non-zero converts to 1 when assigning to a _Bool.

What's not fine is people creating their own compatibility booleans where they define true as 1, as that would indeed break(rather odd..) code such as

    bool a = someInt & 0x02;
    if (a == true) 

If the bool above is not the C99 _Bool, but just a typedef to another integer type, you end up with if(0x02 == 1) evaluating to false.