To what extent is it permissible to combine C and C++?

Question

I'm writing a chat server for class. I'd like to use C's network protocols, but I'm more comfortable programming in C++, particularly in terms of string manipulation.

As I understand it, you can combine the two in a single file and compile for C++ and it'll still accept the C code so long as the proper #include's are there.

What are the limitations on this? What should I look out for? Is there anything in particular from C that will not work in a .cpp file?

Answer 1

You should be able to #include and use standard headers including the networking headers in C++ without doing anything special.

There are some differences between C and C++, but its unlikely you'll run into any problems because of it.

One difference is enums. In C, an enum is just an int. In C++, an enum is an actual type. This code is valid C, but invalid C++.

enum sport {
    hockey,
    baseball,
    soccer,
    vollyball
};

enum sport s = 5;

Compiling this with g++ gives

test.c:11: error: invalid conversion from ‘int’ to ‘sport’

Here is more information on mixing C and C++.