Check if bool is defined in mixed C/C++

Question

So I\'m having issues with some code that I\'ve inherited. This code was building fine in a C-only environment, but now I need to use C++ to call this code. The header p

Answer 1

You can use C99's bool:

#ifndef __cplusplus
#include <stdbool.h>
#endif

bool myBoolean; // bool is declared as either C99's _Bool, or C++'s bool data type.

Why should you use this?

For compatibility with other C99 code. _Bool is commonly used in C99 Code, and is very useful. It also grants you the ability to have a boolean datatype without the need to typedef a lot of stuff, as behind the scenes, _Bool is a datatype defined by the compiler.

Answer 2

Because bool is a basic type in C++ (but not in C), and can't be redefined.

You can surround your code with

#ifndef __cplusplus
typedef unsigned char bool;
static const bool False = 0;
static const bool True = 1;
#endif

Answer 3

I had this "'char' followed by 'bool' is illegal" problem in VS also. The problem for me was I did not end my class declaration with a semi-colon- which I was not expecting to be the issue as this was in the header file and the problem was coming up in the cpp file! eg:

class myClass
{

}; // <-- put the semi colon !!

Answer 4

You should use the __cplusplus macro:

#ifndef __cplusplus
#ifndef _BOOL
typedef unsigned char bool;
static const bool False = 0;
static const bool True = 1;
#endif
#endif 

Check out this link to the C++ FAQ for further details.