How do I solve LNK2005: already defined

Question

I'm working on a project with Lua and Luabind to C++. Now, in every class I want to export to C++, I write a static method Register like this:

In Button.h:

static luabind::scope Register();

In Button.cpp:

luabind::scope falcon::Button::Register()
{
    return 
        luabind::class_<Button, Button*>("Button")
        .def(luabind::constructor<float, float, float, float>());
}

For every class I already exported to Lua, this works fine. But for Button.cpp, this doesn't seem to work.

I get the following linker error:

1>luabindd.lib(luabindd.dll) : error LNK2005: "public: __thiscall luabind::detail::class_base::~class_base(void)" (??1class_base@detail@luabind@@QAE@XZ) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: __thiscall luabind::detail::function_object::function_object(int (__cdecl*)(struct lua_State *))" (??0function_object@detail@luabind@@QAE@P6AHPAUlua_State@@@Z@Z) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: virtual __thiscall luabind::detail::function_object::~function_object(void)" (??1function_object@detail@luabind@@UAE@XZ) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: __thiscall luabind::detail::invoke_context::operator bool(void)const " (??Binvoke_context@detail@luabind@@QBE_NXZ) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: __thiscall luabind::detail::invoke_context::invoke_context(void)" (??0invoke_context@detail@luabind@@QAE@XZ) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: void __thiscall luabind::detail::object_rep::set_instance(class luabind::detail::instance_holder *)" (?set_instance@object_rep@detail@luabind@@QAEXPAVinstance_holder@23@@Z) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: void * __thiscall luabind::detail::object_rep::allocate(unsigned int)" (?allocate@object_rep@detail@luabind@@QAEPAXI@Z) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: class luabind::detail::class_rep * __thiscall luabind::detail::object_rep::crep(void)" (?crep@object_rep@detail@luabind@@QAEPAVclass_rep@23@XZ) already defined in Button.obj
1>luabindd.lib(luabindd.dll) : error LNK2005: "public: class luabind::detail::cast_graph const & __thiscall luabind::detail::class_rep::casts(void)const " (?casts@class_rep@detail@luabind@@QBEABVcast_graph@23@XZ) already defined in Button.obj
1>LINK : warning LNK4098: defaultlib 'LIBCMT' conflicts with use of other libs; use /NODEFAULTLIB:library
1>D:\Users\THijs\Dropbox\3DAE\Platform Development\Falcon Engine\main\FalconEngine\Debug\FalconEngine.exe : fatal error LNK1169: one or more multiply defined symbols found

Anyone got any ideas?

Answer 1

I just solved the error by defining & declaring the function in the headerfile... Perhaps anyone can explain this to me why this has to be done for this class and not for, let's say, the 10 other ones I want to register with Lua?!

It's kind of weird, because I implement the function in those other classes in the .cpp...