CCS: where can select C or Cplusplus compiler in CCS?

yanzhen fu said:

reasion is "bool" just can be use in C

That is incorrect.  bool is a built-in type in C++, just like int.  It is not a built-in type for C.  What is typically done in C is #include <stdbool.h>, then use bool just like any other type.  In fact, the code you show above is from the header file <stdbool.h>  .  I'm not sure why you show it.

Thanks and regards,

-George

The macro __cplusplus is predefined by the compiler.  If the code being compiled is C++, then this symbol is defined and has a non-zero value. Otherwise, it is not defined.  At the same time, the keyword bool is not defined for C, but it is defined for C++.  

So, this test from stdbool.h ...

#ifndef __cplusplus

is true when C code is being compiled, false otherwise.  

How does the compiler know when the source code is C++?  Under most circumstances, the file extension controls it.  If the file extension is .cpp, then the code is C++.  If the file extension is .c, then the code is C.  

Thus, when C code is being compiled, that code in stdbool.h creates a definition for bool that can be used in C code.  When C++ code is being compiled, that code does nothing.

Thanks and regards,

-George