Home > Cannot Be > Why We Cannot Overload Some Operators

Why We Cannot Overload Some Operators


For example:

class Y {
void f();
// ...

class X { // assume that you can overload .
Y* p;
Y& operator.() { return *p; }
void f();
Note that a function overloading expr1?expr2:expr3 would not be able to guarantee that only one of expr2 and expr3 was executed. ... Redefining operators in C++ Operators that cannot be Overloaded - WHY? My initial guess is that overloading the operator will almost always violate number one or two of the principles given in the link above. useful reference

The "I" in this quote is Bjarne Stroustrup. Can I sell a stock immediately Wrong way on a bike lane? Not sure how this could be overridden as the language currently stands. What is the reasoning behind why the ratio test works?

Why Some Operators Cannot Be Overloaded In C++

Single word for the act of being susceptible? This would necessarily complicate the calling code though because it would have to take into account lambda call semantics where no lambda was logically present The ternary operator would need to Load New Code Enter the above shown code: * Inform me about updated answers to this question Related Questions View Answer What is a scope resolution operator?

At the time, I considered the following arguments conclusive: If obj is a class object then obj.m has a meaning for every member m of that object's class. Previous examples of large scale protests after Presidential elections in US? The meaning of the overload will rarely be obvious or clear or it will deviate from its original known semantics. Which Operator Cannot Be Overloaded In C++ Using Friend Function are allowed, so perhaps some clever but appalling dynamic dispatch hack that allows for expressing dot product as matrix1 .

What is the common, normally open, normally closed? Operators That Cannot Be Overloaded In C++ View Answer In C++, what is a constructor,destructor? What skills do Big Data analysts need to have? Source: CoolInterview.com I think the above answer is not appropriate .

According to me all these operators use name instead of operand ,so we can`t pass any name (either of variable,class) to

What additional semantics would you be trying to implement? Operators Cannot Be Overloaded In C# See Bjarne's quote in my answer. –bta Mar 15 '11 at 18:11 | show 3 more comments up vote 0 down vote Defining "operator bool" is enough for ?: to work. In an overloaded version of any of these operators, both operands are always evaluated (in an unspecified sequence). What is the impact of Big Data on Internet of Things (IoT) Industry?

Operators That Cannot Be Overloaded In C++

How to prove that authentication system works, and that the customer is using the wrong password? share|improve this answer answered Jul 30 '13 at 17:28 DUman 1,16258 add a comment| up vote 1 down vote The short and accurate answer is simply "because that's what Bjarne decided." Why Some Operators Cannot Be Overloaded In C++ share|improve this answer edited Mar 15 at 17:51 T.J. Why Scope Resolution Operator Cannot Be Overloaded operator, it wouldn't serve any purpose.

If you want that, do it explicitly by making them private. http://bovbjerg.net/cannot-be/why-certain-operators-cannot-be-overloaded.php What is booting? There are compilers that perpetuate their incompatibilities with the standard just because their clients use those incompatible features. C++0x fixes this with the ability to tag conversion operators as explicit, and then fiddling the verbiage of the standard to say that certain cases in which you might think the Why Can't We Overload Some Operators In C++

Hot Network Questions Limit computation technology in a futuristic society How to handle swear words in quote / transcription? I just didn't see the need to introduce the special case of overloading a ternary operator. Solving a discrete equation I am seen in darkness and in light, What am I? this page Look at the example in bta's link to see the issue Stroustrup is talking about.

What are the modules included in Apache Hadoop Project? Why Dot Operator Cannot Be Overloaded why some operators cannot be overloaded? Is adding the ‘tbl’ prefix to table names really a problem?

Visual Studio Languages , Windows Desktop Development > C++ Standards, Extensions, and Interop Question 0 Sign in to vote Why we can't overload the C operators .

cond ? I looked for an explanation as to why in C++ Operator Overloading but did not find one describing why this isn't possible. Why is the 'You talking to me' speech from the movie 'Taxi Driver' so famous? We Can Change The Basic Meaning Of An Operator In C++ That is, operator overloading can apply only to your own classes.

Can an object *immediately* start moving at a high velocity? more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed What is the use of copy constructor? http://bovbjerg.net/cannot-be/why-some-operators-cannot-be-overloaded.php All parameters must be evaluated.

Now we assume that I overload + operator, so C1+C2 internally translated as c1.operator+(c2) Now assume for the time beings you can overload '.' operator. That means you can't invent new operators. Since one is already allowed, then disallowing the other makes sense, and avoids lots of problem! –Nawaz Mar 15 '11 at 18:05 4 @TommyA: It allows a smart pointer object Consider:

X a[10];
X* p = &a[3];
X* q = &a[3];
p++; // p points to a[4]
// thus the integer value of p must be
// sizeof(X) larger than the

Do we need one to handle Big Data? OneStopSAP.com - SAP EBooks, Tutorials, Articles, FAQs, Jobs, Training Institutes etc. I can think of none. Please include your IP address in your email. 403.

There's also an indirect version, ->*. –Ben Voigt Mar 15 '11 at 18:02 8 i want range operator :. Does a list of the non-letter ASCII symbol macros exist? Please use code.geeksforgeeks.org, generate link and share the link here. Anurag Goyal can new operator also can be overloaded ??? This would be just one more of those cases (i.e.

My boss asks me to stop writing small functions and do everything in the same loop more hot questions question feed lang-cpp about us tour help blog chat data legal privacy For example, it makes sense to overload + and += for strings. operator* and operator-> are there so you can make your own pointer classes. Answer should be complete in itself.

There should not be any Gramatical Errors. instead as ->? 42 Dot (“.”) operator and arrow (“->”) operator use in C vs. Join them; it only takes a minute: Sign up Why can't you overload the '.' operator in C++? Furniture name for waist-high floor-sitting shelf cabinet thing How do I deal with my current employer not respecting my decision to leave?