Programming Forums > Application Development > C++

Ben.Dougall · Jul 12th, 2007, 8:04 PM

I'm currently making a library for a bunch of general tasks. I currently have about 6 classes to make into a library. Up until now, i have been going strictly .hpp files, with all the content in a .hpp instead of .hpp/.cpp . Instead of killing myself over switching everything and not having it work, i made a simple project ( static library ).

So i have two files:
Encryption.hpp

(Toggle Plain Text)

#ifndef GUARD_Encryption_hpp
#define GUARD_Encryption_hpp

#include <string>

namespace BenLib
{
	class Encryption
	{
	private:
		Encryption(void);
	public:	
		~Encryption(void);
		static void Encrypt( std::string &text );
	};

}
#endif

Encryption.cpp

(Toggle Plain Text)

#include "Encryption.hpp"

namespace BenLib
{
	void Encryption::Encrypt( std::string &text )  
	{
		for ( unsigned i = 0; i < text.size(); ++i )
			text[i] = text[i] - 5;
	}
}

So it comes out with a .lib file ( so i make a inc folder for the .hpp, and a lib file for the .lib, add it to the VC++ Directories ( includes and libraries sections ).

When i test it, i get a linker error for BenLib::Encryption::Encrypt. It recognizes the fact Encryption.hpp exists, but it doesn't link to Encryption.lib. I've searched online for this, with no prevail.

Any help would be absolutly amazing, and very much appriciated... I'm about to go crazy trying to figure it out.

DaWei · Jul 12th, 2007, 9:08 PM

Header files should be declarations, not working code. It's not easy to tell from your post if you actually figured this out and handled it. I would recommend that you learn precisely what a build process does.

Ben.Dougall · Jul 12th, 2007, 9:44 PM

I'm starting to port everything into seperate files ( aka headers = class declarations/method prototypes, cpp's holding method bodies )

Now its the issue of getting a linker error when i try to make this a library through VC++ directories.

The Dark · Jul 13th, 2007, 6:48 AM

You have to add the library to your project, or add the library name to the project settings under "Linker - Input" (I think). Just pointing to the library directory in the directory settings isn't enough.

l2u · Jul 19th, 2007, 4:24 PM

In VC 2005 right click on project's name -> Linker -> Input -> Additional dependencies and select the library.

Jul 12th, 2007, 8:04 PM	#1
Ben.Dougall Programmer Join Date: Jul 2007 Location: London, Ontario, Canada Posts: 34 Rep Power: 0	Issues with creating Library I'm currently making a library for a bunch of general tasks. I currently have about 6 classes to make into a library. Up until now, i have been going strictly .hpp files, with all the content in a .hpp instead of .hpp/.cpp . Instead of killing myself over switching everything and not having it work, i made a simple project ( static library ). So i have two files: Encryption.hpp (Toggle Plain Text) #ifndef GUARD_Encryption_hpp #define GUARD_Encryption_hpp #include <string> namespace BenLib { class Encryption { private: Encryption(void); public: ~Encryption(void); static void Encrypt( std::string &text ); }; } #endif #ifndef GUARD_Encryption_hpp #define GUARD_Encryption_hpp #include <string> namespace BenLib { class Encryption { private: Encryption(void); public: ~Encryption(void); static void Encrypt( std::string &text ); }; } #endif Encryption.cpp (Toggle Plain Text) #include "Encryption.hpp" namespace BenLib { void Encryption::Encrypt( std::string &text ) { for ( unsigned i = 0; i < text.size(); ++i ) text[i] = text[i] - 5; } } #include "Encryption.hpp" namespace BenLib { void Encryption::Encrypt( std::string &text ) { for ( unsigned i = 0; i < text.size(); ++i ) text[i] = text[i] - 5; } } So it comes out with a .lib file ( so i make a inc folder for the .hpp, and a lib file for the .lib, add it to the VC++ Directories ( includes and libraries sections ). When i test it, i get a linker error for BenLib::Encryption::Encrypt. It recognizes the fact Encryption.hpp exists, but it doesn't link to Encryption.lib. I've searched online for this, with no prevail. Any help would be absolutly amazing, and very much appriciated... I'm about to go crazy trying to figure it out. __________________ My site :: http://www.freewebtown.com/dougalbe I'll try to be nicer, if you try being smarter.

Jul 12th, 2007, 9:08 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Header files should be declarations, not working code. It's not easy to tell from your post if you actually figured this out and handled it. I would recommend that you learn precisely what a build process does. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Jul 12th, 2007, 9:44 PM	#3
Ben.Dougall Programmer Join Date: Jul 2007 Location: London, Ontario, Canada Posts: 34 Rep Power: 0	I'm starting to port everything into seperate files ( aka headers = class declarations/method prototypes, cpp's holding method bodies ) Now its the issue of getting a linker error when i try to make this a library through VC++ directories. __________________ My site :: http://www.freewebtown.com/dougalbe I'll try to be nicer, if you try being smarter.

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Jul 13th, 2007, 6:48 AM	#4
The Dark Expert Programmer Join Date: Jun 2005 Posts: 852 Rep Power: 4	You have to add the library to your project, or add the library name to the project settings under "Linker - Input" (I think). Just pointing to the library directory in the directory settings isn't enough.

Jul 19th, 2007, 4:24 PM	#5
l2u Newbie Join Date: Mar 2007 Posts: 24 Rep Power: 0	In VC 2005 right click on project's name -> Linker -> Input -> Additional dependencies and select the library.

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Programming Forums > Application Development > C++

Issues with creating Library