First of all: Your functions void my_int_func(int x) and void my_int_func2(int y) do not return anything (return type void). They just prompt the input parameters to stdout. What you probably want is something like that #include <iostream> using namespace std; int my_int_func(int x) { return x; } int my_int_func2(int x) { return x; } void … Read more
You can’t take the address of a function definition, you can take the address of a function value. This works: g := &f Playground example: https://play.golang.org/p/BokYCrVmV_p solved What are function pointers good for in Go if you can’t assign them values?
No, function members cannot be declared in C structs (only in C++). The convention is to pass the struct pointer as the first argument in the functions when doing object oriented programming. Also, C++ really does the same thing, the “this” pointer is passed as the first argument, it is just hidden. struct stack{ int[10] … Read more
The pointer-to-member operators .* and ->* have lower precedence than function call syntax. You need to do: (b1.*ptr)(); solved pointer to a member function of a class
That code is not a declaration, but it can be interpreted as an expression. (*I_dont_know())[(int) ((*ptr))] Call the function I_dont_know with no arguments. This function returns a pointer to something. Dereference the returned pointer to get some object. Meanwhile, dereference the value of ptr and cast it to an int value. Then pass that int … Read more
The API is confusing: What is namelen ? is it the length of the initial prefix of name that is the name of the student? In this case you should allocate one extra byte for the null terminator and copy the name appropriately. is it the maximum length for the student name? Again if this … Read more
if you write in header file static PFNGLGETERRORPROC glGetError; every c/cpp have own private copy of glGetError and it not conflict with other because it static – so different cpp files use different versions of glGetError – in one cpp unit you init one version and it !=0, when you enter to another cpp unit … Read more
Your a is a temporary object in fun(). I fyou want fun() to change the pointer to a you’ll need to take the pointer as reference: int fun(int*& a) { a = fun2(); } Note that this interface is probably severely broken. solved I lose pointer or an address? It acts like never happen [closed]
If you absolutely need to call a function by pointer you will need to use a pointer to member function instead of a pointer to function. A pointer to member function has a different declaration syntax that includes the class type the function belongs to. In your case the parameter declaration would look like int … Read more
It is pretty wonky, it wants to return the default error handler. So you have to pass a pointer to a variable. Like this (untested): xmlGenericErrorFunc handler; initGenericErrorDefaultFunc(&handler); If I understand your intentions properly, this is not the function you actually want to use to suppress errors. Use xmlSetGenericErrorFunc() instead. You can use initGenericErrorDefaultFunc() to … Read more
There are implicit and explicit conversions. A cast is always an explicit conversion and uses the (type) cast operator. C has quite decent type safety when it comes to pointers. Apart from the special case of null pointer conversions, the only implicit pointer conversion allowed is between an object pointer and a pointer to void. … Read more
Yes, functions are located in a specific place in memory. In the context of Virtual Memory (opposed to physical caches), they are stored below the Heap and below a section called the Data (global variables) in a section called Text. All of this is loaded up when the executable is read; this is all done … Read more