Codelite MinGW G ++链接器错误

Question

I'm having a linker issue with mingw on codelite. When I put the .hpp and .cpp files in main where I'm unit testing, everything works fine.

Here's my .hpp file:

class ITPropertiesBase
{
public:
    virtual ~ITPropertiesBase(){}
    virtual const char *getName() = 0;
};



template <typename T>
class Properties : public ITPropertiesBase
{
public:
    Properties(const char *name, T value);
    ~Properties();

    const char *getName();

private:
    const char *m_name;
    T m_value;
};

Here's my .cpp file:

template <typename T> Properties<T>::Properties(const char *name, T value) : m_name(name), m_value(value)
{
}

template <typename T> Properties<T>::~Properties()
{
}

template <typename T> const char* Properties<T>::getName()
{
    return m_name;
}

And here's my main:

#include <iostream>
#include <vector>
#include <string>
#include "Properties.hpp"

int main(int argc, char **argv)
{
    const char *testInput = "test";

    std::vector<ITPropertiesBase*> as;
    as.push_back(new Properties<int>(testInput, 5));
    return 0;
}

And here's the linker output:

C:\Windows\system32\cmd.exe /c "C:/MinGW-4.8.1/bin/mingw32-make.exe -j4 -e -f  Makefile"
"----------Building project:[ Interfaces - Debug ]----------"
mingw32-make.exe[1]: Entering directory 'E:/CodeLite/ElysiumEngine/Interfaces'
C:\MinGW-4.8.1\bin\g++.exe   -c  "E:/CodeLite/ElysiumEngine/Interfaces/main.cpp" -g -O0 -Wall  -o ./Debug/main.cpp.o -I. -I.
C:\MinGW-4.8.1\bin\g++.exe   -c  "E:/CodeLite/ElysiumEngine/Interfaces/Properties.cpp" -g -O0 -Wall  -o ./Debug/Properties.cpp.o -I. -I.
C:\MinGW-4.8.1\bin\g++.exe  -o ./Debug/Interfaces @"Interfaces.txt" -L.
./Debug/main.cpp.o: In function `main':
E:/CodeLite/ElysiumEngine/Interfaces/main.cpp:11: undefined reference to `Properties<int>::Properties(char const*, int)'
collect2.exe: error: ld returned 1 exit status
mingw32-make.exe[1]: *** [Debug/Interfaces] Error 1
mingw32-make.exe: *** [All] Error 2
Interfaces.mk:79: recipe for target 'Debug/Interfaces' failed
mingw32-make.exe[1]: Leaving directory 'E:/CodeLite/ElysiumEngine/Interfaces'
Makefile:4: recipe for target 'All' failed
2 errors, 0 warnings

Anyone know what's going on?

Answer 1

This might apply to you:

• Move header files out of source directory.

It works when they are all in the same folder or not, it is best to relocate them. You need to tell the compiler where they are at, in relation to your project.

change to #include <Properties.hpp>

Then place header files into a include directory.

Then in compiler flags, add include directory for header files. typically a directory called include. For example:

-I../include/

This compiler flag will include the parent directory's include folder. All header files in it will become visible to the compiler. Typically all source code or cpp files, are bundled together. Meaning all in the same parent folder for each codelite project.

• One other thing, try moving your templates into header files.

Reference http://codelite.org/LiteEditor/ProjectSettings .

edit:added bullets