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Why We Cannot Overload Some Operators

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up vote 12 down vote favorite It is reasonable that sizeof and typeid cannot be overloaded, but I can't see the harm in overloading ?:, .* and .. It's a binary operator, but only the left-hand side is used during overloading. What is the impact of Big Data on Technology Industry? could be similarly overloaded. have a peek here

A kind of Proxy. –ddaa Feb 6 '09 at 12:12 2 @Gamecat: Read through this proposal to add the ability to overload operator. or an object referred to by . Conversely, what would be the benefit of allowing this? –Lightness Races in Orbit Mar 15 '11 at 17:58 1 Please forgive my ignorance but is .* really an operator or Forbidden.You don't have permission to view this page.https://www.quora.comPlease email inquiries@quora.com if you believe this is an error.

Why Some Operators Cannot Be Overloaded In C++

That means you can't invent new operators. There are compilers that perpetuate their incompatibilities with the standard just because their clients use those incompatible features. We try not to make the language mutable by redefining built-in operations (though that rule is violated for = out of dire need, and for unary &). It's really not obvious what you would overload ?: for ...

For example:

class Y {
public:
void f();
// ...
};

class X { // assume that you can overload .
Y* p;
Y& operator.() { return *p; }
void f();
Answer should be complete in itself. You can overload operator-> and operator* but not operator. Which Operator Cannot Be Overloaded In C++ Using Friend Function 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 significance of the robot in the sand? The operator takes a boolean input and returns one of two possible resolutions. OneStopGRE.com - of GRE EBooks, Tutorials, Articles, FAQs, Jobs, Training Institutes etc. Hot Network Questions What is the meaning of ''cry oneself"?

For more details, see D&E. Operators Cannot Be Overloaded In C# think of this: SomeClass."SomeString!!" These overloadings prohibit compiler's lexer from parsing the file correctly. 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 In order to support ternary the operator would either need to Take a lambda for each value so it could produce them on demand.

Operators That Cannot Be Overloaded In C++

As such, they're essentially identical to an overloaded ternary operator in this respect. But I think it was the parser issue combined with the feeling that it wouldn't buy much. Why Some Operators Cannot Be Overloaded In C++ Y* p; Y& operator.() { return *p; } void f(); // ... }; void g(X& x) { x.f(); // X::f or Y::f or error? } This problem can be solved in Why Scope Resolution Operator Cannot Be Overloaded And how could you do overloading resolution? –curiousguy Aug 26 '15 at 10:19 add a comment| up vote 40 down vote Stroustrup said C++ should be an extensible, but not mutable

Consider something like: p != NULL ? http://macinstruct.net/cannot-be/which-all-operators-cannot-be-overloaded.html All of which are unique behaviors. –Ben Voigt Mar 15 '11 at 18:06 1 . What skills do Big Data analysts need to have? As you're well aware, other parts of parsing C++ are much more difficult. –Jerry Coffin Jul 30 '13 at 17:55 1 Quite. Why Can't We Overload Some Operators In C++

That said there are no technical reasons I am aware of that prevented these operators from being overloaded. Since it is devoted primarily to flow control, changing what it does for some types of operands is unlikely to accomplish anything very useful. That means you can'toverload the scope resolution operator since it has no arguments. Check This Out Browse other questions tagged c++ operator-overloading ternary-operator or ask your own question.

The dot (attribute access) operator was seen as too close to the core of the language to allow overloading. Why Dot Operator Cannot Be Overloaded Is there a technical reason for this? Please include your IP address in your email. 403.

Category Operators in C++ Interview Questions & Answers - Exam Mode / Learning Mode Rating (3.5) By 97 users Added on 8/18/2011 Views 6059 Rate it! * * * * *

Can anyone please give me clarification what's wrong with overriding those operators? cond ? Overloading new and delete operators Browse more C / C++ Questions on Bytes Question stats viewed: 11549 replies: 2 date asked: Nov 22 '09 Follow this discussion BYTES.COM 2016 Formerly We Can Change The Basic Meaning Of An Operator In C++ In C++, following operators can not be overloaded: . (Member Access or Dot operator) ?: (Ternary or Conditional Operator ) :: (Scope Resolution Operator) .* (Pointer-to-member Operator ) sizeof (Object size

Find the rate of change at a point on a polynomial How to handle a common misconception when writing a Master's thesis? What is the impact of Big Data on Real estate Industry? and ->), then you cannot really access the class members. http://macinstruct.net/cannot-be/which-of-the-following-operators-cannot-be-overloaded.html Solving a discrete equation I am seen in darkness and in light, What am I?

for a class X, we would be unable to access members of X by normal means; we would have to use a pointer and ->, but -> and & might also How to make an assembler. This would be just one more of those cases (i.e. You'd have needed additional grammar rules just for this token. –James Kanze Jul 30 '13 at 17:50 1 @JamesKanze: I was editing to cover that.

Source: CoolInterview.com Answered by: Ankur Bamby | Date: | Contact Ankur Bamby Nice answer, but it does not suite for :? 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 The standard could deprecate them, to encourage compiler warnings, for example.) –James Kanze Jul 31 '13 at 9:05 | show 2 more comments up vote 6 down vote One of the share|improve this answer edited Jan 27 '13 at 15:56 leemes 27.1k1168131 answered Feb 6 '09 at 12:09 ddaa 29.7k63652 add a comment| up vote 27 down vote Stroustrup has an answer

It's quick & easy. Objective-C 5 Overloading [] in C++ to return lvalue 2 Why I cannot overload the :: operator? 0 designing a dot product operator in c++ 3 Ambiguity not picked up by Why does Cutie act like this and lesser robots listen to it?