Read this for detail : // 1 define a function pointer and initialize to NULL int (TMyClass::*pt2ConstMember)(float, char, char) const = NULL; // C++ class TMyClass { public: int DoIt(float a, char b, char c){ cout << “TMyClass::DoIt”<< endl; return a+b+c;}; int DoMore(float a, char b, char c) const { cout << “TMyClass::DoMore” << endl; … Read more
A function object in JavaScript is one thing. A function call is a different thing. You’re using the latter, by including parentheses after the function name*, but you need the former, without parentheses. This allows setTimeout to later invoke the function itself by using the passed-in object. Assuming you do actually want 5 seconds (rather … Read more
There are a few pieces to this that allow all of these combinations of operators to work the same way. The fundamental reason why all of these work is that a function (like foo) is implicitly convertible to a pointer to the function. This is why void (*p1_foo)() = foo; works: foo is implicitly converted … Read more
You need to build a parameter pack of numbers and unpack them template<int …> struct seq { }; template<int N, int …S> struct gens : gens<N-1, N-1, S…> { }; template<int …S> struct gens<0, S…> { typedef seq<S…> type; }; // … void delayed_dispatch() { callFunc(typename gens<sizeof…(Args)>::type()); } template<int …S> void callFunc(seq<S…>) { func(std::get<S>(params) …); … Read more
The syntax is wrong. A member pointer is a different type category from a ordinary pointer. The member pointer will have to be used together with an object of its class: class A { public: int f(); int (A::*x)(); // <- declare by saying what class it is a pointer to }; int A::f() { … Read more
Function pointers in C Let’s start with a basic function which we will be pointing to: int addInt(int n, int m) { return n+m; } First thing, let’s define a pointer to a function which receives 2 ints and returns an int: int (*functionPtr)(int,int); Now we can safely point to our function: functionPtr = &addInt; … 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
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
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