ncurses & stringstream incompatibility

[Null]

I have a weird problem when including both <curses.h> and <sstream> headers:

// This doesn't compile and I get a lot of errors
#include <curses.h> // only because I included curses before sstream
#include <sstream>

int main()
{
std::stringstream ss;

}

Errors:

In file included from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_pair.h:60,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_algobase.h:66,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/char_traits.h:41,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/ios:41,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/istream:40,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/sstream:39,
from D:\C++\sudas\test\main.cpp:27:
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:56:19: error: macro "move" requires 2 arguments, but only 1 given
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:81:36: error: macro "move" requires 2 arguments, but only 1 given
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:82:30: error: macro "move" requires 2 arguments, but only 1 given
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:83:32: error: macro "move" requires 2 arguments, but only 1 given
In file included from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_algobase.h:66,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/char_traits.h:41,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/ios:41,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/istream:40,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/sstream:39,
from D:\C++\sudas\test\main.cpp:27:
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_pair.h:93:34: error: macro "move" requires 2 arguments, but only 1 given
[...]
files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/ios:41,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/istream:40,
from c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/sstream:39,
from D:\C++\sudas\test\main.cpp:27:
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:56: error: 'std::move' declared as an 'inline' variable
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:56: error: template declaration of 'typename std::remove_reference< <template-parameter-1-1> >::type&& std::move'
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:57: error: expected primary-expression before 'return'
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:57: error: expected '}' before 'return'
c:\program files\mingw\bin\../lib/gcc/mingw32/4.4.0/include/c++/bits/move.h:59: error: expected declaration before '}' token
Process terminated with status 1 (0 minutes, 1 seconds)
43 errors, 0 warnings

// This compiles ok
#include <sstream>
#include <curses.h>

int main()
{
std::stringstream ss;

}

I can't understand why there are no errors when I include ncurses after sstream header. Also, does this happen with other compilers than GCC-mingw?

[helios]

The ncurses header probably defined a macro that the sstream header unknowingly uses.

[guestgulkan]

There is a macro in the the curses.h file called move

So when it is this way around:

// This doesn't compile and I get a lot of errors
#include <curses.h> // only because I included curses before sstream
#include <sstream> 

You get the errors because the preprocessor sees this macro first, and then tries to substitute it
in all the following header files - because there is also a move function in the sstream
related headers - this macro substitution will obviously make a nonsense of the sstream related
headers.


When it is this way around:

// This compiles ok
#include <sstream>
#include <curses.h> 

there is no problem ebcause the preprocessor sees the sstream related headers first - and there is no problem.

So the lesson here is if you want to use the curses header and the standard c++ headers - include
the curses header last.

[m4ster r0shi]

Yes, that's probably what happens. I also want to add that just because including sstream before curses works, this doesn't mean that you should do it. Take a look at these:

This one won't compile:

using namespace std;

#define getline(a,b) (cout << "asdf" << endl)

#include <iostream>
#include <string>

int main()
{
    cout << "yo!" << endl;

    return 0;
}

This one compiles ok, but...

using namespace std;

#include <iostream>
#include <string>

#define getline(a,b) (cout << "asdf" << endl)

int main()
{
    cout << "even if this compiles..." << endl;
    cout << "it is dangerous to use!\n" << endl;

    cout << "enter your name: ";
    string name;

    getline(cin,name);

    cout << "hello, " << name << endl;

    return 0;
}

Find another way...

[moorecm]

The header file should probably #undef move when it is done with it. Unless it is meant to be available for users... Make a mental note that when writing header files with macros to undefine them when you're done with them (whenever possible).

[m4ster r0shi]

Ah, right. In that case there should be no problem. But just to be sure, I guess you could do it yourself:

#include <sstream>
#include <curses.h>
#undef move 

EDIT: This would also work:

#include <curses.h>
#undef move
#include <sstream> 

[Null]

Also there will be problems when using erase() and clear(). I googled a little bit and found that I need to define NCURSES_NOMACROS or NOMACROS before includeing curses:

#define NOMACROS
#include <curses.h>
// ... 

or

#define NCURSES_NOMACROS
#include <curses.h> 

But this doesn't work for me (probably because I'm using PDCurses)

[helios]

int     erase(void);
int     clear(void);
int     move(int, int);

These are true functions for me. Maybe you're using an old version?

[Null]

Damn it! I clicked the big green "Download now" button on sourceforge and it downloaded version 2.4 while the newest version is 3.4...