Thread: Converting c to c++, help!

Hi,

I am trying to convert a complex c program to c++ to make it easier to maintain. I am trying to complie the c code using g++ and I get the following error:

error: invlid conversion from 'void *' to 'char *'

I am freeing up some memory in the c program. The code that causes the error is:

Code:

seq=ckfree((void *)seq);

This calls the following function:

Code:

void *ckfree(void *ptr)
{
	if (ptr == NULL)
		warning("Bad call to ckfree\n");
	else {
	 	free(ptr);
		ptr = NULL;
	}
	return ptr;
}

The variable seq is a char*.
Does anyone know what could be causing the error? Is it something that is not allowed in c++, that is allowed in c? Also does anyone has links to information on things to look out for when converting c to c++?

If anyone can help it would be much appreciated.
Mark

That gets rid of that particular error I am having. But I am getting them all over the place. The function ckfree that I have in my first post is used to free up the memory I am using. It just prints an error if the ptr is null.
The thing is that the code works in c, but does not work in c++. Does anyone know why this is? Why do I have to convert back to a char *? And will this still free up the memory? A void * is just any type of pointer right?

Thanks
Mark

Code:

void* pVoid = 0;
char* pChar = 0;

pChar =  pVoid; //error

pChar = static_cast<char*>(pVoid); //ok

I will give that a try.

> I am trying to convert a complex c program to c++ to make it easier to maintain.
rewrite it then.

Unless you count a 'cast-fest' which results from your quick hack as being more maintainable.

It will only ever look like C converted to C++ unless you sit down and actually spend some time thinking about how best to implement it as a true C++ program.

It will end up being effectively a rewrite. I want to do it in steps though, so I would like to have the code compiling as I am going along with it.