Question

I need to save some data and the only viable option is a std::string; so I get a bool array passed as a void*. Now I need to save it in a way that I can convert it into a std::string and be able read a void* to a bool[] from that exact string. Sadly I got lost in conversion.

f(const void* data, int length){

   bool** boolPointer = (bool**)(data);
   bool boolArray[length];

   for (int i=0; i<=length; i++){
       boolArray[i] = p[sizeof(bool)*i];
   }

   std::string s = (std::string&)boolArray;
}

I’m pretty sure the last line is no viable conversion, but that was my attempt.

Answer 1

Does this work for you?

char f(bool b)
{
    return b ? '1' : '0';
}

int main()
{
    // let's just consider whatever is there in this uninitialized array
    bool buf[100];

    std::string s;

    // transform and copy (convert true to '1' and false to '0')
    std::transform(&buf[0], &buf[99], std::back_inserter(s), f);

    std::cout << s << std::endl;
}

If you are on C++11, you can use the following code snippet

int main()
{
    bool buf[100];

    std::string s;

    std::transform(&buf[0], &buf[99], std::back_inserter(s), [](bool const &b){ return b ? '1' : '0'; });
    std::cout << s << std::endl;
}