A problem with templates

[dv916]

I am having a problem with C++ templates which is actually quite embarrassing for me to admit to since I predict a lot of you will figure my problem out faster than it took me to write this post but I've exhausted my patience for right now. I wrote this short snippet in Linux with GCC.

HelloWorld.h

template<class MessageClass>
	class HelloWorld
	{
		public:
			void MessageOne();
			void MessageTwo();
			void MessageThree();
	};
	
#include "HelloWorld.cc"

HelloWorld.cc

using namespace std;

template<class MessageClass>
void HelloWorld<MessageClass>::MessageOne()
{
	cout << "MessageOne()";
}

I get the following errors:
"HelloWorld.cc:5: error: expected init-declarator before '<' token"
"HelloWorld.cc:5: error: expected ';' before '<' token"

[Narue]

What line does the error refer to, and how are you compiling your program?

[dv916]

It's referring to line that says:

void HelloWorld<MessageClass>::MessageOne()

in the "HelloWorld.cc" file. Here is the output I get

Compiling file: main.cc ...
g++  -I/home/david/Projects/HelloWorld/src -I/home/david/Projects/HelloWorld   -Wall   -g  -c "main.cc" -o "main.o"
In file included from HelloWorld.h:1,
                 from main.cc:2:
HelloWorld.cc:4: error: expected init-declarator before '<' token
HelloWorld.cc:4: error: expected `;' before '<' token
Completed ... unsuccessful
Total time taken: 2 secs

Now it says line 4 (not too sure why) but I assure you that the code is the same as shown above.

[Narue]

Is there any particular reason you're including the .cc file in the .h file instead of the other way around?

[dv916]

If I am not mistaken, that is the way my professor used to do it when it came to templates. I already tried "including" the other way around and all the compiler did was re-compile endlessly a hundred times or so (I hope that made sense). I'm at work right now but I'll try again. Any other problems? Suppose there is some kind of syntax error?

[Narue]

>all the compiler did was re-compile endlessly a hundred times or so
A hundred times or so isn't quite endless. Generally it's not recommended that you include .cc files. The conventional method is like so:

// HelloWorld.h
#ifndef HELLOWORLD
#define HELLOWORLD

template<class MessageClass>
	class HelloWorld
	{
		public:
			void MessageOne();
	};

#endif

#include <iostream>
#include "HelloWorld.h"

using namespace std;

template<class MessageClass>
void HelloWorld<MessageClass>::MessageOne()
{
	cout << "MessageOne()";
}

>Suppose there is some kind of syntax error?
There's nothing wrong with your syntax, otherwise I would have jumped on it straight away. Tested on three compilers (one of those being G++), the code compiles cleanly and runs properly with a test driver. So I have to assume that the source of the problem is elsewhere, or something funky is happening when you include the source file.

Could you post a complete example? Something that I don't have to add to or edit heavily to make legal enough for compilation? ;)