Questions tagged [member-pointers]
82 questions
5
votes
2 answers
Is printing of a member pointer to an int defined
Suppose I have this code:
#include
struct Mine
{
int a;
int b;
};
int main()
{
int Mine::* memberPointerA = &Mine::a;
int Mine::* memberPointerB = &Mine::b;
std::cout << memberPointerA;
std::cout << "\n";
…
DarthRubik
- 3,927
- 1
- 18
- 54
5
votes
1 answer
C++ Pointer to member of member
//#define NOT_WORKS
#define HOW(X) 0
struct A {
};
struct B {
A a;
};
struct C {
B b;
};
int main(int argc, char **argv) {
A B::*ba = &B::a; // ba is a pointer to B::a member
B C::*cb = &C::b; // cb is a pointer to…
jdavidls
- 348
- 1
- 5
5
votes
1 answer
Compile error: unresolved overloaded function type
I try to compile the following with g++ 4.7.2:
template
struct A {
struct B {
T t;
template
T get() {
return this->*M;
}
};
B b;
T get() {
return…
Paul Draper
- 78,542
- 46
- 206
- 285
4
votes
2 answers
Does Haskell have pointers/references to record members?
I can create and reference relative pointers to struct members in C++ using the ::*, .*, and ->* syntax like :
char* fstab_t::*field = &fstab_t::fs_vfstype;
my_fstab.*field = ...
In Haskell, I can easily create temporary labels for record getters…
Jeff Burdges
- 4,204
- 23
- 46
4
votes
1 answer
Dynamically allocated member pointer is not zero initialized?
Consider the following code, where T is a member pointer:
#include
struct Foo { double v = 0; };
int main()
{
using T = double Foo::*;
T p1 = nullptr;
T p2 = T();
T p3{};
T * pp4 = new T();
T * pp5 = new T{};
assert(p1 ==…
Sedenion
- 5,421
- 2
- 14
- 42
4
votes
1 answer
Type of pointer to member from base class
I have a problem regarding member pointers. The following code fails to compile using both Oracle Solaris Studio 12.2's CC and cygwin GCC 4.3.4 but works with Microsoft Visual C++ 2010:
struct A {
int x;
};
struct B : public A…
Mike
- 68
- 4
4
votes
1 answer
Reversing pointer to data member
Hi I am trying to figure out if it is legal (by the C++) standard to compute an offset of a member of a class (in order to reverse it).
class A
{
public:
int a, b, c, d;
};
template
ParentClass const *…
Sergey L.
- 21,822
- 5
- 49
- 75
4
votes
2 answers
Member function wrapper with a single argument template?
I made a template function which takes a member function as a parameter.
However, since the class has to be declared before it can be used as part of the member function parameter, I have to make it a separate parameter:
template
stands2reason
- 672
- 2
- 7
- 18
4
votes
0 answers
Comparison of Virtual Function Pointers in C++
Say I want to check to see whether a subclass has implemented one of it's parent's virtual functions (never mind whether this smells of bad architecture... it's an exercise). If I wanted to see if two regular functions were identical, I could just…
stett
- 1,351
- 1
- 11
- 24
4
votes
1 answer
Derived class cannot use member pointer to protected base class member
include
class Base
{
protected:
int foo;
int get_foo() { return foo; }
};
class Derived : public Base
{
public:
void bar()
{
int Base::* i = &Base::foo;
this->*i = 7;
printf("foo is %d\n",…
Daniel Skarbek
- 554
- 4
- 14
4
votes
1 answer
C++ strict aliasing rules and pointers to members
The following code yields warning in G++:
#include
#include
template
Q T::*pointer_to(P T::*p, Q P::*q)
{
typedef Q T::* output_ptr;
// warning: dereferencing type-punned pointer will…
Fedor Trushkin
- 41
- 2
4
votes
2 answers
get type of member memberpointer points to
I would like to extract the type of the member a member pointer points to.
template
void demo(myClass& instance, void* ptr) {
instance.*member = *reinterpret_cast(ptr); // can the someType in this line be…
ted
- 4,791
- 5
- 38
- 84
3
votes
4 answers
Can a single function pointer point to multiple classes member function
Here are the requirements posed by my application. I have a class A, that accepts a function pointer say cFunc, Basically in my implementation of A, I have it call cFunc multiple times.
The cFunc pointer itself should point to different functions…
Nicomoto
- 473
- 2
- 7
- 15
3
votes
1 answer
Understanding pointer to member of class of type - no polymorphism
I thought it is straightforward that a 'pointer to member of class T of type DerivedT' can be used as a 'pointer to member of class T of type BaseT' if BaseT is base of DerivedT. The analogy seems to be obvious at least to me as DerivedT* can be…
Broothy
- 659
- 5
- 20
3
votes
2 answers
is there a use for &func or class::func in c++?
This seems inconsistent. Why do we use &Example::func instead of Example::func? is there a use for Example::func or &exampleFunction? it doesnt seem like we can make a reference to a function so that rules out Example::func. and i cant think of a…
user34537