错误： 变量‘xxx’被设定但未被使用 [-Werror=unused-but-set-variable]
warning: variable set but unused – C++ Forum
出现这个警告的原因可能是，基本上，你移除这个变量也不会对你的程序造成什么影响。
warning: variable ‘ret’ set but not used [-Wunused-but-set-variable]
warning: variable ‘turn’ set but not used [-Wunused-but-set-variable]
receiving these errors even though I am using them
Please guide me to the solution of these warnings!
I use turn on lines: 10, 17 25
I use ret on line: 33
int OlsonAttack(int mode, int opponent) //ATTACK FUNCTION{int column;char row;int ret;//******STATUS VERIABLES******//static int board[BS_GRID_ROWS][BS_GRID_COLS]; // board will not changestatic bool turn; //allows turn to end || not to fire > oncestatic bool hit; //fired is for shot per turn//***********************************//switch(mode) {case BS_MODE_NEW_GAME: //NEW GAME turn = true;for (row = 0; row < BS_GRID_ROWS; row++) //search/increment rowfor(column = 1; column < BS_GRID_COLS; column++) //search increment column board[row+'A'][column] = 0;break;case BS_MODE_CONTINUE_GAME: //CONTINUE GAME (no error)turn = true;if (!hit) {do {row = rand() % BS_GRID_ROWS;column = rand() % BS_GRID_COLS;}while (board[row+'A'][column] == 1);board[row+'A'][column] = 1; //Marks a probed unit of space on arrayret = fire[opponent](row + 'A', column + 1);}break;}return 0;}> I use turn on lines: 10, 17 25
line 10:staticboolturn;definition, not a use
line 17 and 25:turn =true;setting, not a use
> I use ret on line: 33ret = fire[opponent](row +'A', column + 1);setting, not a use
Bascally, if you remove those two variables, the behaviour of your program should not change.