Including C headers inside a C++ program

Question

I have a C++ program (.cpp) inside which I wish to use some of the functions which are present inside the C header files such as stdio.h, conio.h, stdlib.h, graphics.h, devices.h etc.

I could include the stdio.h library inside my cpp file as : #include <cstdio>. How do I include the other library files?

How do I add the graphics.h library?

I'm using Microsoft Visual Studio 6.0 Enterprise Edition and also Turbo C++ 3.0.

Solution 1

For a list of C standard C headers (stdio, stdlib, assert, ...), prepend a c and remove the .h. For example stdio.h becomes cstdio.

For other headers, use

extern "C"
{
  #include "other_header.h"
}

Solution 2

If you put this inside your headers:

#ifdef __cplusplus
extern "C"
{
#endif

// your normal definitions here

#ifdef __cplusplus
}
#endif

Then it will work for both C and C++ without any problem ...

Hope this helps...:)

Solution 3

I'm not sure what you need exactly, but if you want to use old fashioned C functions inside you C++ program, you can easy include them by removing the .h and add a "c" prefix.

for example if you want to include math.h use

#include <cmath>

Solution 4

Just include them inside a extern "C" block an they should work like expected.

Solution 5

You can #include them using their original names. #include <stdio.h> works just fine in C++.

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Comments

[David Thornley]

The C standard headers are required to work in standard C++, although you may be putting more than you like into the global namespace. Non-standard headers, like conio.h or graphics.h, may not be set up properly, and may need to be wrapped in extern "C" { ... }. Check your implementation documentation.