如何在函数中返回指针数组？

Question

So I have an array of pointers that references 3 instances of a class, I need to create a function that gets the references to those 3 instances and returns it into that array.

Here is what I have been trying:

#include<cstdlib>
#include<cinttypes>
#include<random>

//Random number generator
uint8_t rand(uint8_t max){
    std::default_random_engine generator;
    std::uniform_int_distribution<uint8_t> distribution(0,max);

    return distribution(generator);
}

class MyClass{
    //...
}
myClass[100];

MyClass * getReferences(){ //What should the type of this be?
    MyClass * arrayOfPointers[3];

    for(uint8_t i=0;i<2;++i){
        arrayOfPointers[i]=&myClass[rand(2)];
    }

    return arrayOfPointers;
}

int main(){
    MyClass * arrayOfPointers[3]=getReferences();

    return EXIT_SUCCESS;
}

Answer 1

As mentioned you are returning a pointer to a local variable which is incorrect.

Use standard library containers to avoid the pitfalls and woes of C-style arrays.

std::array<MyClass *, 3> getReferences()
{
    std::array<MyClass *, 3> arrayOfPointers;

    for(int i=0; i < 2; ++i) // don't use tiny int types of small for loops. it's not faster and it's harder to maintain
    {
        arrayOfPointers[i] = &myClass[rand(2)];
    }

    return arrayOfPointers;
}

int main()
{
    std::array<MyClass *, 3> arrayOfPointers = getReferences();
}

Answer 2

Returning a pointer to a local variable is incorrect in C++. It can lead in memory violation errors. If you want to return an array from the function you should use dynamic memory allocation. MyClass * arrayOfPointers = new MyClass[3]; . Don't forget to delete it, after using. delete[] arrayOfPointers;