Question

Good evening 🙂

I’m playing around with g++ and makefiles. I’ve gotten to this point:

foo.h:

#ifndef _FOO_H_ #define _FOO_H_  #include 'bar.h'  class foo { private:     bar something; public:     bool start();     bool stop(); };  #endif // _FOO_H_ 

Foo.h is eventually included in my main cpp file so I can set things in motion by calling start/stop.

void somewhere() {     foo* hihi = new foo;     hihi->start();     delete hihi; } 

Then there’s bar.h:

#ifndef _BAR_H_ #define _BAR_H_  class bar {  };  #endif // _BAR_H_ 

g++ doesn’t seem to like it however:

g++  (some_flags) -c main.cpp In file included from main.cpp:2: foo.h:8: error: ‘bar’ does not name a type 

I’m using makefiles, and tried a combination of things like:

main.o: main.cpp foo.h bar.h 

Even though I don’t think I should have to add bar.h here, shouldn’t including it in foo.h be enough?

To clarify, this is roughly how it’s set up now (yes I know this can be done in a more efficient manner):

main.o: main.cpp foo.h     $(CC) $(CFLAGS) -c main.cpp  foo.o: foo.h foo.cpp     $(CC) $(CFLAGS) -c foo.cpp  bar.o: bar.h bar.cpp     $(CC) $(CFLAGS) -c bar.cpp 

What’s going on? I figure it’s something I’m missing about g++ and the way it handles header includes, point me in the right direction please!

edit – found the solution:

Doh! I feel dumb right now. Was messing around with boost::asio and kind of forgot I still left this on top of my headers somewhere: using boost::asio::ip::tcp;

Let’s just say there’s a boost::asio::ip::tcp::bar function 😀

Oh well, thanks anyway!

Answer 1

Was messing around with boost::asio and kind of forgot I still left this on top of my headers somewhere: using boost::asio::ip::tcp;

Let’s just say there’s a boost::asio::ip::tcp::bar function

Dan Saks explains some reasons why you should typedef your class names, even though it might seem redundant.

Well, you’ve run into real life situation where typedefing a class would have probably helped you find your problem a little easier:

 class bar {  // ...  };  typedef class bar bar; 

Generates this more meaningful message if there’s a function named bar() already declared:

In file included from C:\temp\foo.h:4,                  from C:\temp\test.cpp:4: C:\temp\bar.h:7: error: `typedef class bar bar' redeclared as different kind of symbol C:\temp\test.cpp:1: error: previous declaration of `void bar(int)' C:\temp\bar.h:7: error: declaration of `typedef class bar bar'