memory-address

I have this in my testing.cpp: class Supp{ public: virtual Supp* add(Supp& val) = 0; }; class SubA : public Supp{ public: int val; SubA(int a){ val = a; } int getVal(){ return val; } Supp* add(Supp& value){ SubA& a = dynamic_cast<SubA&>(value); int tempVal = a.getVal(); int sum = val + tempVal; SubA b =SubA(sum); return &b; } }; and the lines SubA b = SubA(sum); return &b; gives and error because itreturns the address to a local variable which is very bad to do, so i changed it to SubA* b =new SubA(sum); return b; and it works fine with no errors, But is this not basically the same thing? why

struct Data { int a; std::string b; float c; }; std::string* allocateDataAndGetString() { Data* dataPtr(someAllocator.allocate<Data>()); return &dataPtr.b; } Data* getBaseDataPtrFromString(std::string* mStringMember) { // ??? } int main() { std::string* stringPtr(allocateDataAndGetString()); Data* dataPtr(getBaseDataPtrFromString } I have a Data instance allocated on the heap, and a pointer to its std::string b; member. How do I get the base address of the Data instance the string is a member of, taking into account offsets and padding, in a standard way? I've tried subtracting sizeof(int) and

Here is just a test prototype : #include <iostream> #include <string> using namespace std; int main() { int a=10; char b='H'; string c="Hamza"; cout<<"The value of a is : "<<a<<endl; cout<<"The value of b is : "<<b<<endl; cout<<"The value of c is : "<<c<<endl<<endl; cout<<"address of a : "<<&a<<endl; cout<<"address of b : "<<&b<<endl; cout<<"address of c : "<<&c<<endl; return 0; } Why the address of variable 'b', which is of character type, not printing? The << operator in your code is overloaded in C++ 11. It doesn't conflict with any of other types like int or string , but it takes pointer

If 2 programs are running, and one program stores a number at a memory address, and if I know that memory address, and hard code it into the 2nd program and print out the value at the address, would it actually get that info? Does C++ allow programs to access any data stored in RAM no matter if it is part of the program or not? On system with no virtual memory management and no address space protection this would work. It would be undefined behavior from the point of view of the C standard, but it would produce the behavior that you expect. Bad news is that most computer systems in use these

I have this code that edits addresses in a game to get unlimited ammo and what not, and I found out that the addresses are different for every computer, sometimes every time you restart the game, so how would I manage making this work still even though they change. If you get the address you're looking for, and then search for that address in memory to find the address of the pointer to that data, and then search for that address in memory so you can find the address of the pointer to it, and so on, you may eventually find an address that does not change. Then, at runtime, you can use that as

How come you can assign an address to an integer variable like this,the complier will not give an error. i always though you can only assign integer values to a integer variable int a=0x28ff1c You can do the same for a char variable, the complier will not give a error char b=0x28ff1c It will output on the console screen rubbish value for char b and a random value for int a cout<<b <<endl; cout<<a; Can someone explain to me why there is a difference in the output for char b and int a. Can someone aslo explain to me why a char variable and integer variable can have addresses assign to it The

I have a class to represent a 3D vector of floats: class Vector3D { public: float x, y, z; float * const data; Vector3D() : x(0.0), y(0.0), z(0.0), data(&x) {} } My question is: are x, y, and z going to be allocated sequentially in memory such that I can assign the address of x to data and later use the subscript operator on data to access the vector components as an array? For example, sometimes I may want to access the vector components directly: Vector3D vec; vec.x = 42.0; vec.y = 42.0; vec.z = 42.0; And sometimes I may want to access them by offset: Vector3D vec; for (int i = 3; i--; ) vec