Now C::f() can be used like this: /* C code: */ For example: // C++ code:Įxtern 'C' double call_C_f(C* p, int i) // wrapper function virtual functions) from C, you need to provide a simple wrapper. If you want to call member functions (incl. Naturally, this works only for non-member functions. Now f() can be used like this: /* C code: */ Just declare the C++ function extern 'C' (in your C++ code) and call it (from your C or C++ code). For example: // C++ codeĭouble dd = h(i,d) // error: unexpected arguments

So you can’t call function declared extern 'C' with the wrong number of arguments. Note that C++ type rules, not C rules, are used. The definitions of the functions may look like this: /* C code: */ Just declare the C function extern 'C' (in your C++ code) and call it (from your C or C++ code). Obviously you don’t have much of aĬhoice if you’re not able to alter your C-style code (e.g., if it’s from a third-party). The point is that the effort required to clean up your C-style code may be less than theĮffort required to mix C and C++, and as a bonus you get cleaned up C-style code. The down-side is that you’ll need to update yourĬ-style code in certain ways, basically because the C++ compiler is more careful/picky than your CĬompiler. Possibly -hopefully!- discover some bugs) in your C-style code. That pretty much eliminates the need to mix C and C++, plus it will cause you to be more careful (and In addition, you’ll need to read the rest of this section to find out how to make your C functions callable by C++īTW there is another way to handle this whole thing: compile all your code (even your C-style code) using a C++Ĭompiler. Your C and C++ compilers probably need to come from the same vendor and have compatible versions (e.g., so they.Your C++ compiler should direct the linking process (e.g., so it can get its special libraries).You must use your C++ compiler when compiling main() (e.g., for static initialization).Here are some high points (though some compiler-vendors might not require all these check with your compiler-vendor’s How to mix C and C++ What do I need to know when mixing C and C++ code?

C coder