Fill Array of unspecified Size with data

Question

So i am learning C++ right now and i am pretty stuck right now. I have been researching in the Internet Form some time now, but could Not find a solution to my Problem. Maybe because i did not know what to look after..

And sry for the maybe misleading title, but here is the question:

Lets say I have a struct called Data with an int Array and some other members

struct Data{
...
uint8_t values [];
}

Now i have a Method test

void test (uint8_t *buffer, size_t buffer_size)
{
...

}

In that method i make an instance of Data and i want to assign the value stored in the buffer to that Array of the instance of Data and i have no Idea how to so this. Not sure, but maybe i need a Pointer-Pointer?

Thanks in advance! Cheers

You should not use a pointer for any of the code you have shown. That is unless this is an academic requirement. — drescherjm, Dec 14 '19 at 18:22
Well it kind of is an academic requierment (Not to use pointers, I have got an Framework i have to use which includes the struct and the Method). — sebp24, Dec 14 '19 at 18:28
If you are not permitted to use std::vector you could create your own vector class using new[] and delete[] — drescherjm, Dec 14 '19 at 18:36
Related: [https://stackoverflow.com/questions/13431567/how-to-make-an-array-with-a-dynamic-size-general-usage-of-dynamic-arrays-maybe](https://stackoverflow.com/questions/13431567/how-to-make-an-array-with-a-dynamic-size-general-usage-of-dynamic-arrays-maybe) — drescherjm, Dec 14 '19 at 18:37
There should be a better example however I have to leave now.. — drescherjm, Dec 14 '19 at 18:39

score 0 · Answer 1 · answered Dec 15 '19 at 17:51

In c++ you can use the STL std::vector<>. You can declare it in :

struct Data{
...
std::vector<uint8_t> values;
}

Then in the Method Test :

void test (uint8_t *buffer, size_t buffer_size)
{
...
    struct Data istanceData;
    for (int i=0 ; i < buffer_size; ++i){
        istanceData.values.push_back(buffer[i]);
    }
}

Remember to dinamically allocate Struct Data (and return it's pointer) if you want to use it outside "test" function. You can also pass an extra parameter to the "test" function and pass the istanced Struct Data with reference in this way:

void test (uint8_t *buffer, size_t buffer_size, struct Data &instanceData)
{
...
    for (int i=0 ; i < buffer_size; ++i){
        istanceData.values.push_back(buffer[i]);
    }
}

Cant, i dont have enough Reputation yet – sebp24 Dec 18 '19 at 08:09 — sebp24, Dec 18 '19 at 08:09

Fill Array of unspecified Size with data

1 Answers1