Is it normal that smart pointers can't solve a problem?

[jaffe15]

Hi!
I was wondering how normal it is that a problem can't be solved with smart pointers? On my current project I can't seem to use smart pointers (which I am a new to) to solve a specific problem. Is that usual? I kind of got the impression that the vast majority of problems can and should be solved with smart pointers.

[jonnin]

its just a type. You may as well ask if many problems can be solved using type int. You can pretty much always force fit one into any code snippet.

Smart pointers are better than raw pointers.
Often, not having any pointers at all is the right answer, far more often than new coders think because pointers are stressed so much in the classroom.

[mbozzi]

The vast majority of problems can and should be solved with smart pointers

I feel obligated to remind you of Maslow's hammer:
https://en.wikipedia.org/wiki/Law_of_the_instrument

Smart pointers are not a complete replacement for plain pointers. They are occasionally useful, but there are some things about their usage that aren't entirely obvious.

Can you be more specific about your actual problem.

[Peter87]

Smart pointers is a tool that you can use to improve your code but it's unlikely to be the thing that decides whether you're able to solve a problem or not.

jonnin wrote:

Often, not having any pointers at all is the right answer ...

I can't agree more.

... far more often than new coders think because pointers are stressed so much in the classroom.

Another reason is because we learn other languages that always use new when creating class object. It's usually not called pointers in those languages but it behaves very similar. Learning that this is not the best way in C++ and how to handle the object lifetimes in a good way usually takes some time.

[deleted account xyzzy]

A better question might be: "Is it normal that pointers can't solve a problem?"

Smart pointers are a tool to make managing an object's memory use easier than using a non-smart pointer. Can a non-smart pointer solve every problem? No, but it can create more problems if the memory isn't managed properly.

Not every regular pointer uses heap memory via new/delete, all smart pointers do use heap/free store memory.

In the Before Times, before C++, C used pointers to pass objects into functions and access heap memory using manual memory management. When and where the memory was released was a major problem.

C++ introduced std::auto_ptr, the first C++ smart pointer.
https://en.cppreference.com/w/cpp/memory/auto_ptr

One problem is the workings of an auto_ptr was "wonky," copying one transferred the ownership to the destination, with some weird results. So the current crop of smart pointers was created. And std::auto_ptr was deprecated, then later removed from the C++ toolbox.

C++ also introduced "references," aliases to the object. Less overhead and no manual memory management at all. A reference is just a different name for the object.

Swapping two numbers using pointers:

#include <iostream>

void Swap(int*, int*);

int main()
{
   int a { 5 };
   int b { 125 };

   std::cout << "Before swap(*, *), a: " << a << ", b: " << b << '\n';

   Swap(&a, &b); // <-- address-of operators

   std::cout << "After swap(*, *), a: " << a << ", b: " << b << '\n';
}

void Swap(int* a, int* b)
{
   int temp { *a };

   *a = *b;

   *b = temp;
}

Before swap(*, *), a: 5, b: 125
After swap(*, *), a: 125, b: 5

Using references:

#include <iostream>

void Swap(int&, int&);

int main()
{
   int a { 5 };
   int b { 125 };

   std::cout << "Before swap(&, &), a: " << a << ", b: " << b << '\n';

   Swap(a, b);

   std::cout << "After swap(&, &), a: " << a << ", b: " << b << '\n';
}

void Swap(int& a, int& b)
{
   int temp { a };

   a = b;

   b = temp;
}

Before swap(&, &), a: 5, b: 125
After swap(&, &), a: 125, b: 5

References are generally preferred over pointers, even smart pointers. Pointers and References, while they are important tools every programmer needs to know and understand, are not the "one size fits all solution" for every problem.

Smart pointers relieve the programmer from the burden of manually managing memory use, though they can introduce problems of their own. They are a trade-off that is best assessed on an individual basis.

Choose the right tool for the right job at hand. Not every programming problem is a nail.