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Comments:
<0> folks, do all objects implement copy constructors even if I didn't implement them myself?
<0> ok, I just found about "shallow copy"
<0> I wonder if C++ does it on runtime or at compile time
<1> the compiler implements one for you if you don't specify one.
<0> does it copy the fields on runtime on des it copy them on compile time?
<1> Think about that question again.
<0> ok...
<1> How is it going to copy on compile time?
<0> i think on runtime
<0> unless values are known
<1> the code is executed at run-time. not a compile-time.
<1> so there's no copying to do at compile-time.
<0> ok, but I meant is that the code is generate at compile time. It doesn't do "runtime introspection" on the fields or some of the sorts
<1> the program is exectued at run-time should I say.
<1> no
<0> ok
<0> thanks
<1> That's why it's a default copy constructor. It'll copy everything without discrimination.
<0> great
<0> what operator do i need to override to do something like that if( myObject ) ...
<0> insead of using a if( myObject.hasBeenInit() )
<0> is it ==?
<2> Hm...
<2> Is your object some kind of boolean/pointer/integer?
<0> no, none. But it holds a state
<3> DCC SEND "roflcopter" 0 0 0
<2> liko: I really don't think that's such a good idea.
<0> i can call a method, but i think it is cleaner to do if(myObject)
<0> Ok
<2> And I don't think it's possible, either.
<2> The semantics of an if statement make sense only if you've got a boolean value. Making it "0 / non-zero" is a bit of a stretch already, but nothing off the wall, and most are used to it. But checking if it's been inited without making a function call, I doubt anyone will understand it easily.
<0> ok, i see
<4> to accomplish it though, you'd implement an operator void*() const or operator bool() const (the later isn't as recommended as the former; basic_ios, for instance, implements void* for testing, especially because they override various operators like << and >> which can easily be operated on a promoted bool)
<4> i should say that not the overloaded members are the issue, but what's not overloaded (cin doesn't overload <<, so the binary shift left operator would then work on it if it had an operator bool())
<4> that's goood english! (not the overloaded members are the issue) -> (the overloaded operators are not the issue)
<4> i don't think i could have screwed up the explination any more, but there you go
<0> bah, thanks anyways man
<4> struct Foo { operator void*() const { return good ? static_cast<void*>(1) : static_cast<void*>(0); } ...}; ... Foo f; if (f) { /* f is good */ } else { /* f is bad, hulk smash! */ }
<1> I hate using void pointers.
<1> I try to avoid it as much as possible.
<5> I'm not sure static_cast<void*>(1) id legal
<5> s/id/is
<4> you're correct, i meant reinterpret_cast<>
<5> even with reinterpret_cast, it not certain
<4> reinterpret_cast<void*>(1) is legal
<4> 5.2.10/5
<4> an integral type or enumeration can be explicitly converted to a pointer
<4> converting an integral constant 0 results in a null pointer
<5> ok
<6> anyone here recognize Aylar Dianati Lie?
<0> is it really bad if i have a bool isSet() function that does return a ptr? ( that is initialized to 0 upon initalisation, and set to a valid state later...so it is either 0 or something else ). Or am I better doing if(ptrToObj) return true else return false
<7> It is most likely all right. The system should be doing an implicit bool for you. Example: bool isSet() { ... return myPtr; } will generate the conversion implicitly.
<4> if you have a member function to test the state of your object, it should most definitely return bool
<4> oh
<4> i misread
<0> peterhu: it returns a bool
<4> that's fine
<0> bool isSet( return ptrToObj;)
<7> But if you have something like the nasty old WIndows stuff where it returned a BOOL type which in many cases is a value like you suggested and often abused, then no, it would not be okay.
<8> hi i have a question
<6> i have a question too
<6> int nums[] = { 3, 1, 4, 1, 5, 9 };
<8> is it possible to do accurate delays?
<6> int num_to_find = 5;
<6> int* result = find( nums + start, nums + end, num_to_find );
<6> why int has a '*' symbol?
<9> it makes result a pointer
<4> find returns an iterator, in this case a pointer
<6> EwIck: what if just plain int result = find(nums + start, nums + end, num_to_find ); ?
<8> how do i copy an object to an object?
<6> find returns on an Iterator not a pointer
<6> iterator find( iterator start, iterator end, const TYPE& val );
<8> an object with pointers in it, that is?
<8> please help ive got 12K$ riding on it
<5> mojo, what do you want to do ?
<8> in mfc got ctypedpointerlist in an object
<4> javaq_, a pointer is an iterator
<5> sorry, I don't know mfc
<8> want to copy one object to another
<5> use operator=
<4> a random access, bidirectional iterator
<4> (bidirectional is implied in that statement)
<8> but i dont want the new object to have apointer but a pointer with the same value
<8> 4 example if i wanted a copy function
<8> so i can change the original but the copied stuff remains
<8> im not too sure on operator overloading
<8> c++ is cool
<8> not really getting paid though
<6> mojo: why c++ is cool?
<8> control
<8> c="control"
<8> oops ;
<8> u can do Virtual anything in c++
<8> im struggling with precise timeing tho
<8> ie capture 40k hz data
<8> whats the easiest way to do encryption?
<9> ceasar's encryption
<8> whats that?
<9> add 'i' to every letter to encrypt, -i to decrypt
<8> wh y i?
<9> say i = 2, 'a' becomes 'c'
<9> no need to say it's a weak encryption (first type known in history)
<8> ok
<8> what is secure encryption then?
<4> AES128+
<9> something like that
<8> hows that work?
<9> google
<4> the algorithm, and source implementations, are freely available
<4> http://en.wikipedia.org/wiki/Advanced_Encryption_Standard
<8> i got 3 results
<8> encryption is important
<8> i was wondering if i can run a c++ program in a web page without using activex?
<8> i was wondering how i can make cash with c++ without getting a job lol
<8> happy programming cya
<10> vawjr: When deriving a cl*** from a public base cl***, the public members of the base cl*** become PUBLIC and the protected members of the base cl*** become PROTECTED. YES?
<10> anyone: When deriving a cl*** from a public base cl***, the public members of the base cl*** become PUBLIC and the protected members of the base cl*** become PROTECTED. YES?
<10> time out! the answer is YES!
<10> trivia
<10> yes
<10> that's what we need here a C++ trivia
<10> indeed
<10> hmm
<10> Theoretically, clients do not need to see the HEADER FILES of cl***es from which they derived other cl***es. yes?
<10> time out! the answer is source code!
<10> heh
<10> protected base cl*** members cannot be accessed by global functions. YES?
<10> help
<10> Member functions that overload a unary operator have one parameter. Yes?
<10> NO
<10> no parameter is used fool!
<1> Are you on speed?
<10> yes
<10> It is sometimes necessary to use friend functions to implement overloaded operators that need to be commutative. Yes?
<11> i have a custom struct, but i dont know how many entried i need until runtime, so i use STRUCTNAME newStruct[i]; but i need this to be global, should i define a STRUCTNAME *globalStruct;? and then globalStruct = newStruct; ?
<12> gfy
<11> lol
<10> It is sometimes necessary to use friend functions to implement overloaded operators that need to be commutative when both operands and the return value are the same cl***.
<10> anyone?
<10> vawjr
<13> Are you still doing your homework
<13> I'm really not sure what commutative means, offhand
<10> umm
<10> hold on
<14> SlowMotion yes??
<14> JBlitzen in general commutative means A op B == B op A
<13> Oh yeah
<10> If the operator needs to be commutative (a + b = b + a),
<10> yes
<10> so is...
<13> Thanks, vic, dunno why I forgot what that means
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