CPP

pointer in return function c++

#include <iostream>

using namespace std;

int *getDouble(int* x){
    int *result = new int ((*x) * 2);		// save the result in the heap
    return result;    	//return the address of the result
}

int main(){
    int x=5;
    int *ptr = getDouble(&x);		//the pointer points to the result address
    cout<<*ptr<<endl;
}

pointer in return function c++

#include <iostream>

using namespace std;

int getProduct(int* x){
    *x *= 2;
    return *x;   
}

int main(){
    int x=5;
    cout<<getProduct(&x)<<endl;
}

c++ function return pointer to itself

// To some free-function
struct func_wrap
{
    using f_t = func_wrap(*)();
    f_t func;
    f_t operator()() const noexcept { return func; }
    operator f_t() const noexcept { return func; }
};

using func_t = func_wrap(*)();

// Function to wrap
func_wrap foo() { return func_wrap{foo}; }

func_t bar() { return foo(); }
func_t buz() { return foo()(); }

// Some functor
struct function
{
   function operator()() const noexcept
   {
       return function();
   }
};

function foo(int) { return function(); }
function bar(int) { return function()(); }
function buz(int) { return function()()(); }