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static members

Started by frogant Apr 18, 2001 at 4:28 AM 7 replies 350+ views

Original Post

Apr 18, 2001 at 4:28 AM

hi, I get this linker error when I try to use static data members in c++ classes: unresolved external symbol "public: static int NNTank::m_reference_count" (m_reference_count@NNTank@@2HA) using vc++ 5 pro sp3 what gives?

jwalker

Apr 18, 2001 at 5:06 AM

put this in your cpp file ...

static int NNTank::m_reference_count = 0;

should solve the linker problem ..

Edited by - jwalker on April 18, 2001 10:09:10 AM

Clash Rocker

Apr 18, 2001 at 5:58 AM

I though you had to leave out the "static" in the definition?
.H

    
class foo
{
public:
    static int bar();
private:
    static int spoot;
};
  

.CPP
      
int foo::bar()
{
    //...

}

Edited by - Clash Rocker on April 18, 2001 7:02:32 AM

capn_midnight

404

capn_midnight

Apr 18, 2001 at 12:51 PM

Nope, you use the static each time.

Are you even trying to be intelligent?
''cuz if you are, it ain''t workin''

Down with Tiberia!

arunvb

Apr 18, 2001 at 1:31 PM

I am not sure about other compiler but in VC++, you certainly DONT need to include the static in your definition. It is enough if we mention it in out declaration.

I have a few static variables in my project, where I have the keyword static in the declaration alone. I dont use the keyword static in my definitions. It works perfectly for me.

Thanks
Arun

Clash Rocker

Apr 18, 2001 at 10:33 PM

Well I got around to trying it out on gpp. And it compiled
with zero errors when I left out that static on the function
definition.

null_pointer

Apr 19, 2001 at 10:12 AM

You should not use static in the definition, because that use of static has nothing to do with static data members. This is the correct way to do it:


// in the header file:
class someclass
{
public:
  static int data;
};

// in the source file:
int someclass::data;

merlin9x9

Apr 20, 2001 at 12:41 AM

Right, and it''s the same with other keywords such as virtual and inline.

frogant

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