Tag: input

I am trying to write a couple of template functions that convert back and forth between a value of any data type (within reason) bytewise into a character string.
The idea is to (eventually) store the values in a .bin file, and also to be able to recover the values from said .bin file.
However, I need to get the conversion functions correct, first.
Originally, I wrote a toy function that did both that looked line this:

template<typename T>
void buildabin(T x)
{
    char* X;
    T x_;
    X = (char*)&x;
    memcpy(&x_, X, sizeof(T));
    cout<<x_<<endl;
}

This seemed to work fine.
However, when I tried to separate out the two capabilities, using:

template<typename T>
void buildabin(char*& X, T x)
{
    X = (char*)&x;
}

And:

template<typename T>
void buildaT(char* X, T& x)
{
    memcpy(&x, X, sizeof(T));
}

It seems as if it is doing the conversion to the binary string correctly, however, upon input to “buildaT”, it barfs – after placing some couts for X in various places, for some strange reason, it is not getting even the address of X correctly.
And of course, “little” x just returns garbage.

I have tried every scheme I can to get this to work. It seems it’s a “user error” on my part with respect to input in the “buildaT” function, but I am stuck as to where the error lies.

Here is main, if that helps:

int main()
{
    //char* G = new char(sizeof(double)); //(tried this also)

    char* G = NULL;

    double g;

    cin>>g;

    buildabin<double>(G, g);

    double g_;

    buildaT<double>(G, g_);

    cout<<g_<<endl;


    return(0);
}