address-operator

Get pointer on var obtained via interface

由 大城市里の小女人 提交于 2021-02-11 12:09:28
问题 In the following code var a int var b interface{} b = a fmt.Printf("%T, %T \n", a, &a) fmt.Printf("%T, %T \n", b, &b) output: int, *int int, *interface {} I would expect the type of &b to be a pointer on int. I have two questions: 1) Why is it a pointer on interface{} ? 2) How could I get a pointer on the original type ? 回答1: &b => this is the address operator applied on the variable b , whose type is interface{} . So &b will be a pointer of type *interface{} , pointing to the variable b . If

In C (also C++), how '&' operator works as both address operator and bitwise operator ? As operator overloading is not supported by C

由 一个人想着一个人 提交于 2021-01-28 03:28:10
问题 The operator '&' can be used in both of following way int a; scanf("%d",&a); and printf("%d",1&2) . But different behaviour (for first as address operator and second time as bit-wise operator). I know operator overloading is not there in C. Then how it works ?. Also highlight for c++. 回答1: In "C" language, operators have different meaning when they are used as prefix to expression, suffix to expression or "infix" (between two expressions). Consider '*', which performs multiplication as 'infix

Passing static method as argument, no address-of operator required?

由 ￣綄美尐妖づ 提交于 2019-12-10 19:07:13
问题 class ThreadWorker { public: ThreadWorker(void); virtual ~ThreadWorker(void); static void DoSomething(); }; int main() { boost::thread thread1(ThreadWorker::DoSomething); boost::thread thread2(ThreadWorker::DoSomething); boost::thread thread3(&ThreadWorker::DoSomething); } I'm playing around with Boost.Thread and I notice it doesn't seem to matter whether I use the address of operator (&) or not when passing a static member function as an argument. Does it not matter? And if not, why? Is one

Why can function pointers be used with or without the address of operator? [duplicate]

由 回眸只為那壹抹淺笑 提交于 2019-12-07 08:28:50
问题 This question already has answers here : Why do function pointer definitions work with any number of ampersands '&' or asterisks '*'? (2 answers) Closed 10 months ago . In the book, "Beginning C from Novice to Professional", the author does not use the address of operator when assigning a function to a function pointer. I typed in the code on my compiler both with and without the address of operator and it compiled and performed as expected both times. Why is this and which way would be

Why can function pointers be used with or without the address of operator? [duplicate]

由 ＊爱你＆永不变心＊ 提交于 2019-12-05 17:34:47
This question already has an answer here: Why do function pointer definitions work with any number of ampersands '&' or asterisks '*'? 2 answers In the book, "Beginning C from Novice to Professional", the author does not use the address of operator when assigning a function to a function pointer. I typed in the code on my compiler both with and without the address of operator and it compiled and performed as expected both times. Why is this and which way would be preferred in an enterprise/business setting? int sum(int, int); int main(void) { ... int (*pfun)(int, int); pfun = ∑ pfun = sum; ...

Why would anyone want to overload the & (address-of) operator? [duplicate]

由 别来无恙 提交于 2019-12-04 10:01:45
问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: What legitimate reasons exist to overload the unary operator& ? I just read this question, and I can't help but wonder: Why would anyone possibly want to overload the & ("address-of") operator? some_class* operator&() const { return address_of_object ; } Is there any legitimate use case? 回答1: If you're dealing with any sort of wrapper objects, you might want or need to transparently forward the access to the

Why would anyone want to overload the & (address-of) operator? [duplicate]

由 不问归期 提交于 2019-12-03 04:55:12
This question already has answers here : What legitimate reasons exist to overload the unary operator&? (7 answers) Possible Duplicate: What legitimate reasons exist to overload the unary operator& ? I just read this question , and I can't help but wonder: Why would anyone possibly want to overload the & ("address-of") operator? some_class* operator&() const { return address_of_object ; } Is there any legitimate use case? If you're dealing with any sort of wrapper objects, you might want or need to transparently forward the access to the wrapper to the contained object. In that case, you can't

AddressOf alternative in C#

由 China☆狼群 提交于 2019-12-01 04:49:14
Could anyboby help me with the alternative solution in C# regarding AddressOf operator in VB6 ? AddressOf returns a long value. What way can I get the output in C#? Expanding on Harper Shelby's answer, yes it can be done, but it's generally a code smell to do so in .NET. To get the address of a variable in C#, you can use C-style pointer (*) /address (&) / dereference (->) syntax. In order to do this, you will have to compile the app with the /unsafe compiler switch, as you're bouncing out of the safety net of managed code as soon as you start dealing with memory addresses directly. The sample

AddressOf alternative in C#

由 旧街凉风 提交于 2019-12-01 02:42:17
问题 Could anyboby help me with the alternative solution in C# regarding AddressOf operator in VB6 ? AddressOf returns a long value. What way can I get the output in C#? 回答1: Expanding on Harper Shelby's answer, yes it can be done, but it's generally a code smell to do so in .NET. To get the address of a variable in C#, you can use C-style pointer (*) /address (&) / dereference (->) syntax. In order to do this, you will have to compile the app with the /unsafe compiler switch, as you're bouncing

Can an address be assigned to a variable in C?

由 旧城冷巷雨未停 提交于 2019-12-01 00:24:51
Is it possible to assign a variable the address you want, in the memory? I tried to do so but I am getting an error as "Lvalue required as left operand of assignment". int main() { int i = 10; &i = 7200; printf("i=%d address=%u", i, &i); } What is wrong with my approach? Is there any way in C in which we can assign an address we want, to a variable? Not directly. You can do this though : int* i = 7200; .. and then use i (ie. *i = 10) but you will most likely get a crash. This is only meaningful when doing low level development - device drivers, etc... with known memory addreses. Assuming you
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