Bitwise arithmetic on an integer return value - c++

Question

Here we have a function fire() which accepts two arguments:
A capital letter (char) in the range of 'A' .. 'A'+BS_GRID_ROWS-1 that indicates the row in your grid to attack.
An integer (int) in the range of 1 .. BS_GRID_COLS that indicates the column of your grid to attack.
The return code will be:
0 if there is only open water.
The bit BS_SHIP_HIT will be set, or both BS_SHIP_HIT and BS_SHIP_SANK will be set. In addition, the ship that was hit will be indicated in the lowest four bits of the return code. You may use BS_SHIP_MASK to help extract the number for the ship type.
semi-pseudocode interpretation:
//r is A ... (A + BS_GRID_ROWS - 1)
//c is 1 ... BS_GRID_COLS
fire(char r, int c) {
//some set of commands
if(miss) {
return 0;
else if(sink) {
return hit + sunk + size;
else if(hit) {
return hit;
else {
return miss;
}
}
I am uncertain of exactly how I might go about extracting these individual values (hit, sunk, size) from the return value.
The actual .h file and it's relevant const values are seen here:
#ifndef BATTLESHIP
#define BATTLESHIP
const int BS_SHIP_HIT = 0x10; // Ship is hit, or
const int BS_SHIP_SANK = 0x20; // sank (must also | BS_SHIP_HIT)
const int BS_CARRIER = 1;
const int BS_BATTLESHIP= 2;
const int BS_CRUISER = 3;
const int BS_DESTROYER = 4;
const int BS_SUBMARINE = 5;
const int BS_SHIP_COUNT = 5;
const int BS_SHIP_MASK = 0x0F;
const int BS_CARRIER_SIZE = 5;
const int BS_BATTLESHIP_SIZE= 4;
const int BS_CRUISER_SIZE = 3;
const int BS_DESTROYER_SIZE = 2;
const int BS_SUBMARINE_SIZE = 3;
const int BS_MODE_NEW_GAME = 1;
const int BS_MODE_CONTINUE_GAME = 2;
const int BS_GRID_ROWS = 10; // letters A to J
const int BS_GRID_COLS = 10; // numbers 1 to 10
const int MaxPlayerCount = 65; // Maximum size for following arrays
extern int userIncoming(char, int);
extern int userBattle(int, int);
extern int incomingStub(char, int);
extern int battleStub(int, int);
extern int (*fire[])(char, int);
extern int (*battleship[])(int, int);
extern char const *playerName[];
#endif

Answer 1

Something like this perhaps?
int result = fire(r, c);
if (result & BS_SHIP_HIT)
{
std::cout << "Ship of size " << result & BS_SHIP_MASK << " hit\n";
}
If the BS_SHIP_HIT bit is set in result, the the result of result & BIT_SHIP_HIT will be equal to BS_SHIP_HIT otherwise the result will be zero (which is equivalent to false).
The result of result & BS_SHIP_MASK will be the low four bits in result.
Or lets look at it using the actual bits:
BS_SHIP_HIT is equal to the binary value 00010000 and BS_SHIT_MASK equal 00001111. Lets assume that fire returns 00010101 (BS_SHIP_HIT set and size 5), then the if condition will be
00010000
& 00010101
----------
= 00010000
Then for the printing, the expression will be
00010101
& 00001111
----------
= 00000101