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Why do I get a multiple definition error when linking?

I use these two files here and here .

I created the class in two separate files:

modul1.h

#ifndef MODUL1_H
#define MODUL1_H

#include <iostream>
#include <fstream>

#include "easylogger.h"

class Modul1
{
    public:
        Modul1(std::string name);
    protected:
    private:
        easylogger::Logger *log;
};

#endif // MODUL1_H

and modul1.cpp

#include "modul1.h"

Modul1::Modul1(std::string name):log(new easylogger::Logger(name))
{
    //ctor
    //std::ofstream *f = new std::ofstream(name.c_str(), std::ios_base::app);
    //log->Stream(*f);
    //log->Level(easylogger::LEVEL_DEBUG);
    //LOG_DEBUG(*log, "ctor ende!");
}

Now I want to use this class in another file (main.cpp):

#include "modul1.h"

int main()
{
    std::cout << "Hello world!" << std::endl;
    Modul1 mod1("test.log");
    return 0;
}

When I compile it with the following Makefile, I get the error "multiple definition ...":

g++ main.o modul1.o -o main modul1.o: easylogger::Logger::Format(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': modul1.cpp:(.text+0x0): multiple definition of easylogger:: Logger:: Format (std:: basic_string, std:: allocator > const &) ' main.o: main.cpp:(. + 0x0): modul1.o: easylogger::Logger::WriteLog(easylogger::LogLevel, easylogger::Logger*, char const*, unsigned int, char const*, char const*)': modul1.cpp:(.text+0x2a): multiple definition of easylogger:: Logger:: WriteLog (easylogger:: LogLevel, easylogger:: Logger *, char const *, unsigned int, char const *, charconst *) 'main.o: main.cpp:(. text + 0x2a): collect2: ld 1

( :: blocks )

Modul1, ? , , Ubuntu 64bit g++ 4.4.3

Makefile:

CC=g++
CFLAGS=-c -Wall

all: log_test

log_test: main.o easylogger.h modul1.o
    $(CC) main.o modul1.o -o main

main.o: main.cpp modul1.h
    $(CC) $(CFLAGS) main.cpp

modul1.o: modul1.cpp modul1.h
    $(CC) $(CFLAGS) modul1.cpp
+5
2

, easylogger.h(, , easylogger-inl.h) , modul1.h main.cpp

. , :

modul1.h( #include "easylogger.h" )

#ifndef MODUL1_H
#define MODUL1_H

#include <iostream>
#include <fstream>
//#include "easylogger.h"

namespace easylogger { class Logger; };

class Modul1
{
    public:
        Modul1(std::string name);
    protected:
    private:
        easylogger::Logger *log;
};

#endif // MODUL1_H

modul1.cpp,

#include "modul1.h"
#include "easylogger.h"

Modul1::Modul1(std::string name):log(new easylogger::Logger(name))
{
    //ctor
    //std::ofstream *f = new std::ofstream(name.c_str(), std::ios_base::app);
    //log->Stream(*f);
    //log->Level(easylogger::LEVEL_DEBUG);
    //LOG_DEBUG(*log, "ctor ende!");
}

!

+4

"easylogger-impl.h". easylogger-impl.h. .

, .

easylogger-impl inline, , .

+4

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