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Why We Cannot Overload Sizeof Operator


Sizeofcannot be overloaded because built-in operations, such as incrementing a pointer into an array implicitly depends on it. Nov 22 '09 #1 Post Reply Share this Question 2 Replies Expert Mod 5K+ P: 8,916 Banfa Generally the operators that can't be overloaded are like that because overloading them could Please include your IP address in your email. Source: CoolInterview.com Answered by: pratik arya | Date: 4/25/2010 | Contact pratik arya these operators are not used in other meanigful restriction
for example + used in addition and sign that operators have a peek here

What is booting? It is therefore not possible to overload sizeof, even if the C++ Standard allowed it. Scope resolution and member access operators work on names rather than values. sizeof doesn't need or have any runtime support.

Why Some Operators Cannot Be Overloaded In C++

It is not obvious what benefits such a complication would bring. Source: CoolInterview.com Answered by: Hitesh | Date: 3/7/2010 | Contact Hitesh these type of operator don't there own value,but in overloading not change there own value while overloading that's why if Note that a function overloadingexpr1?expr2:expr3wouldnot be able to guarantee that only one ofexpr2andexpr3was executed. What is the impact of Big Data on Education Industry?

asked 7 years ago viewed 9311 times active 3 years ago Upcoming Events 2016 Community Moderator Election ends Nov 22 Linked 1 How to figure out integer boundaries in C 1 It is merely special syntax which inserts a constant equal to the size of the argument. Operator overloads are simply functions, and do what they do at run time. Which Operator Cannot Be Overloaded In C++ Using Friend Function That means you can't overload operator+ for int or double.

It is evaluated by the compiler not at runtime so you can not overload it with your own runtime code. How Can We Cope with the Impact of Big Data? OneStopMBA.com - MBA EBooks, Tutorials, Articles, FAQs, Jobs, Training Institutes etc. Operator . (dot) could in principle be overloaded using the same technique as used for ->.

Nov 22 '09 #2 reply Expert Mod 5K+ P: 8,922 weaknessforcats All operators that can be overloaded must have at least one argument that is a user-defined type. We Can Change The Basic Meaning Of An Operator In C++ current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list. One could imagine allowing overloading of x::y where x is an object rather than a namespace or a class, but that would - contrary to first appearances - involve introducing new C# TBB updating metadata value Is it possible to check where an alias was defined?

Why Scope Resolution Operator Cannot Be Overloaded In C++

That is, operator overloading can apply only to your own classes. Edit: If the compiler is itself written in C or C++, then you can think of the implementation being something like this: size_t calculate_sizeof(expression_or_type) { if (is_type(expression_or_type)) { if (is_array_type(expression_or_type)) { Why Some Operators Cannot Be Overloaded In C++ It's inside the compiler. Operators That Cannot Be Overloaded In C++ c++ share|improve this question edited Apr 5 '09 at 13:34 Avi 16.5k24460 asked Apr 5 '09 at 12:55 Alien01 3,6791458111 3 what possible use could you have for such an

The exceptions are

. (dot) :: ?: sizeof

There is no fundamental reason to disallow overloading of ?:. navigate here operator then we cant access member in normal way for that we have to use ->. Stroustrup's wanted to allow programmers to use all the operators with user defined data types as well. At runtime, structure sizes are fixed and known, the same as when you write int i = 8 ; nobody actually calculates 8 at runtime. –Anton Tykhyy Apr 5 '09 at Why Can't We Overload Some Operators In C++

why some operators cannot be overloaded? c overloading asked Sep 23, 2015 by no3 Please log in or register to add a comment. 2 Answers +2 votes Best answer In C++, following operators can not be References : http://www.stroustrup.com/dne.html answered Sep 23, 2015 by Swanky selected Nov 9, 2015 by Gaurav Please log in or register to add a comment. 0 votes We are not allowed to http://macinstruct.net/cannot-be/why-we-cannot-overload-operator.html 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?

One could imagine allowing overloading of x::y where x is an object rather than anamespaceor a class, but that would - contrary to first appearances - involve introducing new syntax (to Which Operator Cannot Be Overloaded In C# So it means we cannot change its default behavior? View Answer Difference between a "assignment operator" and a "copy constructor" - Operators in C++ Interview Questions & Answers"> View Answer Define copy constructor?

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What is Apache Hadoop? Unanswered Tags Users Ask a Question Ask a Question Start Coding Today GeeksQuiz GeeksforGeeksIDE Data Structures Algorithms Interview Experiences C Programming C++ Programming Java Programming GATE CS GATE View Answer How can you overload a method? Describe Operator Overloading. Which Are The Operators That Cannot Be Overloaded The rules for this are part of the ABI, and compilers merely implement them.

although it could return something like template int_ operator sizeof() { ... } and I would be a compile time constant depending on T –Johannes Schaub - litb Apr 5 There is no mechanism available by which we can pass 3 parameter during operator overloading.
For other operators, the previous ans is enough. How to handle swear words in quote / transcription? http://macinstruct.net/cannot-be/why-we-cannot-overload-scope-resolution-operator.html What is the impact of Big Data on Information Technology Industry?

Vikash Kumaran C++ allows only to give extra functionalities to an operator. Note that a function overloading expr1?expr2:expr3 would not be able to guarantee that only one of expr2 and expr3 was executed.

Sizeof cannot be overloaded because built-in operations, such as incrementing a operator as it does not take name as parameter.
BTW, the reason we cannot overload :? Similar topics Getting rid of bitwise operators in Python 3?

Source: CoolInterview.com Answered by: jitendra singh | Date: 1/26/2008 | Contact jitendra singh According to Bjarne Stroustrup, the operators ., .* ,:?, :: & sizeof() cannot be overloaded as they take Privacy Policy | Terms and Conditions

Question Everything Upcoming Posts Upcoming Posts.... What does it mean? There should not be any Gramatical Errors.

share|improve this answer answered Apr 5 '09 at 14:58 jwillia3 add a comment| up vote 1 down vote Variable: #define getsize_var(x) ((char *)(&(x) + 1) - (char *)&(x)) Type: #define getsize_type(type) share|improve this answer edited Dec 23 '12 at 11:42 Hongxu Chen 1,9491540 answered Apr 5 '09 at 13:01 Doug 6,0901732 "What do you hope to learn from seeing an I am only passionately curious." - Albert Einstein Thursday, January 12, 2012 Why does C++ not allow overloading ‘.' , ‘:*' , ‘::' and ‘?:' operators?