What is ">?=" operator in c++?

Asked Oct 25 '16 at 07:18

Active Oct 25 '16 at 21:05

Viewed 88 times

I came across this piece of code. Can anyone explain what the operator does? I tried searching SO,internet but couldn't find info on it.

....
int add=0;
for(int i=0; i<l; i++)
   add >?= doit(x+1, y+1, n);
....

I found the code in one of user solutions on TopCoder.

edited Oct 25 '16 at 21:05

asked Oct 25 '16 at 07:18

mtk

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There is no such operator. C++ doesn't allow custom operators. This is probably a macro that's meant to appear as an operator – Panagiotis Kanavos Oct 25 '16 at 07:21
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how do you can write a macro like that? – BiagioF Oct 25 '16 at 07:22
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Can you create a [mcve] with it? If it compiles, what compiler are you using? – juanchopanza Oct 25 '16 at 07:23
You shouldn't but [this CodeProject](http://www.codeproject.com/Articles/31783/Custom-User-Defined-Operators-in-C) tutorial shows how. Should be avoided for the obvious WT? factor. The tutorial uses this macro `#define contains == CCustomOperatorHelper_contains() ==` and overloaded `==` operators to grab the arguments on either side – Panagiotis Kanavos Oct 25 '16 at 07:23
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@BiagioFesta, you can't. A macro name must be a valid identifier token. – StoryTeller - Unslander Monica Oct 25 '16 at 07:23
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@PanagiotisKanavos, in the link you added `contains` is the macro name, which *is* a valid identifier token. `>?=` is not. – StoryTeller - Unslander Monica Oct 25 '16 at 07:25
@StoryTeller yes. And the duplicate shows that this isn't about C++ after all. Just an ancient compiler extension – Panagiotis Kanavos Oct 25 '16 at 07:27
@mtk next time mention the compiler you use. Where *did* you find this code? I think `std::min` and `std::max` were already available 20 years ago – Panagiotis Kanavos Oct 25 '16 at 07:31
*"Finally, your operators have to be a-zA-Z0-9_ based, just like everything else. The reason has to do with limitations in the macro symbols that make it impossible to declare operators like >>> or anything else with a symbol. You can still use really short symbols, though I would capitalize them and avoid using single letters."* your link – BiagioF Oct 25 '16 at 07:31
@PanagiotisKanavos: If you follow the link, you will see that they were *actually* a g++ extension that only applied to c++. – Martin Bonner supports Monica Oct 25 '16 at 07:41
Ah. Maybe that is what you were saying. Sorry. – Martin Bonner supports Monica Oct 25 '16 at 07:41
I found the code in one of user solutions on TopCoder – mtk Oct 25 '16 at 21:05

What is ">?=" operator in c++?

0 Answers0