When I try to compile my program the compiler complains about this line in a .h file that I #included.
ostream & Print (ostream & stream);
How can this be fixed?
views:
49answers:
3
+5
A:
If you #include <ostream>, ostream will be defined in the std namespace:
#include <ostream>
// ...
std::ostream & Print (std::ostream & stream);
GMan
2010-05-22 09:03:24
If your program's not enormous, just put 'using std::ostream' after the #include ; life and lines are both too short to type std:: more than you have to
Tom Womack
2010-05-22 09:22:43
Better may be #include <iosfwd>, that contains only forward declarations.
Matteo Italia
2010-05-22 10:55:32
@Tom Womack: NEVER EVER put using statements in a header file. Life is way to short to sort out the trouble that that will cause when it blows up in your face.
Martin York
2010-05-22 11:13:57
A:
Minimal code for this declaration to compile:
#include <iosfwd>
using namespace std;
BennyG
2010-05-22 09:04:43
Agreed. But I didn't say this code was going into a header file. If you don't have control over the contents of the header file being included, these two lines will get it working from the .cpp file.Regardless, <iosfwd> is a better choice than <ostream> in this case.
BennyG
2010-05-24 08:29:39
A:
Use 'using' if you don't want to pull the whole std namespace, eg :
#include <iosfwd>
using std::ostream;
OneOfOne
2010-08-18 23:52:55