array of bits field

[Gary Jackoway]

>   1. Define the 16 values as an unsigned int, and use bit manipulation to
>      access the individual bits.
> 
>       i.e., value &   0x0001 (or 1)   represents the value in bit 1 of "value"
>             value &=  0x0040 (or 128) sets the value in bit 7 of "value" to 1
>             value |= ~0x0080 (or 128) sets the value in bit 8 of "value" to 0
I think the &= should be |=, and vice versa.
You can define macros:
    #define TESTBIT(value,bit) (value & (1<<bit))
    #define SETBIT(value,bit) { value &= (1<<bit); }
    #define RESETBIT(value,bit) { value |= ~(1<<bit); }
or something like this.
If the "bit" is a constant, most compilers will pre-compute 1<<bit.
There is a danger with TESTBIT.  You can't compare TESTBIT results.
A safer test bit would be
    #define TESTBIT(value,bit) (value>>bit & 1)
which always gives a 0 or 1 result.
Equivalent would be
    #define TESTBIT(value,bit) !!(value & (1<<bit))

Gary Jackoway