It saves you from having to learn those pesky boolean operators... 

if( ((input1 < '1') && (input1 > '9')) ||
    ((input2 < '1') && (input2 > '9')) )
    return INPUT_ERROR;

input1 -= 48;
input2 -= 48;

if( ((input1 < 1) || (input1 > 9)) ||
    ((input2 < 1) || (input2 > 9)) )
    return INPUT_ERROR;

 

Hey! do you have something against code reuse?

If you read carefully, you'll see that the code was not exactly reused. The condition in the first if-statement always fails.

TGV:

If you read carefully, you'll see that the code was not exactly reused. The condition in the first if-statement always fails.

Not always.  What if it's double threaded and those two values change between the evaluation of whether they're less than 1 and greater than 9?

belgariontheking:

What if it's double threaded and those two values change between the evaluation of whether they're less than 1 and greater than 9?

A good compiler should optimize away the second memory read (or the complete comparison), i.e. you have to declare the variables volatile for that to happen. Or you can overload the operator.

strcmp:

you have to declare the variables volatile for that to happen

How do you know they aren't declared volatile in that snippet?

Spectre:

strcmp:

you have to declare the variables volatile for that to happen

How do you know they aren't declared volatile in that snippet?

Easy:

Spectre:

they aren't declared volatile in that snippet

strcmp:

Spectre:

strcmp:

you have to declare the variables volatile for that to happen

How do you know they aren't declared volatile in that snippet?

Easy:

Spectre:

they aren't declared volatile in that snippet

They aren't declared at all in the snippet.

: IF COMPILE ?-GOTO COMPILE-HERE ; IMMEDIATE
: THEN HERE SWAP ! ; IMMEDIATE
: ELSE COMPILE GOTO COMPILE-HERE SWAP HERE SWAP ! ; IMMEDIATE

operator<( const InputType& i, const char& c ) { return rand() < int(c); }

operator<( const InputType& i, const int& n ) { return int(i) < n; }

 

dear sir, the rand() keeps changing, how can i fix this?