Unresolved external symbol, overloading operator== in my class

[gedamial]

Hello.

I'm making a static library. I have a GString class in which I overload some operators (<<, =, [])

I'm now trying to overload the == operator, but I get an unresolved external error from the linker.

namespace ged
{
	namespace Data
	{
		class GString
		{
		        int size;
		public:	
			/* OPERATOR OVERLOADING */
			friend bool operator==(const GString& first, const GString& second);
                 };
         }
}

bool ged::Data::operator==(const GString& first, const GString& second)
{
   // implementation...
}

And this is a screenshot: http://prntscr.com/9p4d53

This is the error i get:
unresolved external symbol "bool __cdecl ged::Data::operator==(class ged::Data::GString const &,class ged::Data::GString const &)" (??8Data@ged@@YA_NABVGString@01@0@Z)

This is the main() code where I get the error

#include <iostream>
#include <string>
#include <conio.h>
#include "gedamial.h"

using namespace std;
using namespace ged::Data;
using namespace ged::Mathematics;

int main()
{
	GString my = "ciao";
	GString my2 = "addio";

	if (my == my2)
		cout << "uguali";

	else
		cout << "non uguali";

	_getch();
	return 0;
}

[coder777]

What compiler do you use?

The gcc shows this error:

gcc wrote:

D:\temp\temp\test2\main.cpp|13|error: 'bool ged::Data::operator==(const ged::Data::GString&, const ged::Data::GString&)' should have been declared inside 'ged::Data'|

Your compiler obviously doesn't think that the implemented function is the friend function of GString.

[gedamial]

I use the MSVC++ compiler

Hmh, so what should I do? Put the implementation in the header file instead of in the separate .cpp?

[Thomas1965]

Your class GString needs to end with };

[gedamial]

It does. My bad copying&pasting the code in the forum.

[coder777]

Hmh, so what should I do? Put the implementation in the header file instead of in the separate .cpp?

Yes.

Or alternatively the gcc is satified when you put it in the namespaces:

namespace ged
{
	namespace Data
	{
bool operator==(const GString& first, const GString& second)
{
   // implementation...
}
         }
}

[gedamial]

That's strange, i can't understand why.

I have a bunch of operator overloads, even this which i declare as friend

.h

friend std::ostream& operator<<(std::ostream& s, const GString& other);

.cpp

std::ostream& ged::Data::operator<<(std::ostream & s, const GString & other)
{
	// ... bla bla bla ...
	return s;
}

But this one works fine.

Mhm, however nevermind

Thanks ;)