Missed Opportunity for Easter Egg

[Manfred Rudolf Bihy]

Not f***ed, but rather elephanted or maybe pachydermed. Cheers!

"With sufficient thrust, pigs fly just fine."

Ross Callon, The Twelve Networking Truths, RFC1925

"Der Berg ruft!"

Me, 2012-05-24

[lewax00]

Of course, how could I be so foolish?

[Matthew Dennis]

or 9 x 6 = 42

[greldak]

In VB that expression will always resolve to False In other languages (C included) you could overload the values for 1 and 2 and/or the operator = or command If Good luck figuring out whats going on with that level of obfuscation. Its not something I would expect to see as a simple expression but it can be useful as a clause especially if you need to build up a complex expression at run time. In practice its more likely that some piece of funcionality is wanted to remain in the codebase but not required to run under normal circumstances - probably debug code although there are better ways of doing it.

[svella]

greldak wrote:

In other languages (C included) you could overload the values for 1 and 2 and/or the operator = or command If
Good luck figuring out whats going on with that level of obfuscation.

I'm pretty sure you're wrong about being able to override either the values or the operator in C (or even C++ for that matter), but I'd welcome a working example.

[Sucramsy]

If 42 is the answer to life the universe and everything then this statement would be true.

[reilly96]

in SQL I use that to create tables with no data

select *
into #t
from table1
where 1=2

[onemorechance]

OriginalGriff wrote:

... my constant values had changed...

Something about that just doesn't seem right ...

[ekolis]

You can do that in Java as well, though it requires boxing conversions...

[OriginalGriff]

That's why it took so long to work it out - it's just not something you expect... :laugh:

Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water

[AspDotNetDev]

Neat trick. :thumbsup:

Thou mewling ill-breeding pignut!

[Kostya Kovalskyy]

compiles on GCC

#define if(X) if(1)

using namespace std;

int main()
{
if (1 == 2) {
cout << "this is executed" << endl;
}
return 0;
}

this would compile on C compiler too, but I just hate using those printfs. But you were right about #defining numbers -- it's impossible. A define identifier name cannot start with a number. But you can overload almost anything else.

[svella]

Hmmm, yeah, well what you've really done is macro replaced an "if" expression (not really overloaded it in the normal sense of the word, but I guess close enough), but have not really succeeded in overloading 1, 2, or ==.

[Kostya Kovalskyy]

Even through it does not really "overload" it, it can still lead to a lot of confusion. In C++ you can also do something like this

#include

class T {
public:
int a;
T(int _a) : a(_a) {}
bool operator==(const T &var) {return true;}
};

using namespace std;

int main() {
#define int T //this is defined here because main returns int, and this causes error if defined earlier
int a = 1, b = 2;
if (a == b) {
cout << "this is evaluated" << endl;
}
return 0;
}
}

Of course, you can always put anything in the == operator so it would behave differently :)

[Kostya Kovalskyy]

If you want to only "subtly" mess it up, and work for most of other cases normally you can do this:

#include

class T {
public:
int a;
T(int _a) : a(_a) {}
bool operator==(const T &var) {
if((a == 1 && var.a == 2) || (a == 2 && var.a == 1)) return true;
else return a == var.a;
}
};

using namespace std;

int main() {
#define int T //this is defined here because main returns int, and this causes error if defined earlier
int a = 1, b = 2;
if (a == b) cout << "this is evaluated";
a = 4, b = 5;
if (a == b) cout << "while this is not" << endl;
return 0;
}

[Keith Badeau]

:laugh: :thumbsup:

[Keith Badeau]

In C++ you can override operators inside of a class.

class foo
{
private:
int num;

public:
foo* operator=(int i) {
this->num = i;
return this;
}
// ...
};

I believe the example is syntactically correct and it is a very contrived an arbitrary example. Numbers cannot be overloaded (In Scheme maybe?) and new operators cannot be created that do not already exist. In C operators cannot be overloaded.

[svella]

Yep, I'm aware of operator overloading and all the attendant mischief possible with it. But I stand by my original statement, that given the original expression 1 == 2, there is no way in C or C++ to overload the values of the integer literals nor is there a way to redefine the meaning of == in a way that would affect it's meaning when used on those literals. But as you cleverly pointed out, you can use the macro processor to redefine if in such a way as to eliminate the expression before the compiler ever sees it.