default arguments in C++

[nebc]

I'm having problems with default arguments in C++. The CamState files
compile just fine but I get an error when I try and compile fvcart.cpp. Here's the error:

../../objdir/FvCartPanel.o(.text+0x3a3c): In function `FvCartPanel::UpdateImage()':
pathcode/fvcart/FvCartPanel.cpp:292: undefined reference to `CamState::still()'
collect2: ld returned 1 exit status

code in FvCartPanel
-------------------------------------------
if(but2->isChecked())
{
if(csp->still()){
// assuming that we've already moved here
posp.set(hs/2, ws/2);
//....

-------------------------------------------
csp is a CamState object

void moveToAbsPanTilt(int pan, int tilt);
bool still(double time = 0.001);

void set_framerate(int framerate);
-------------------------------------------
Here is the CamState.cpp

bool CamState::still(double time) {
/* has the camera stopped moving? - using a hack for
now, absolute amount of time since last movment */
//if (motortimer.elapsed() > 500) // used to be 800

// 500 wasn't working at all. Kept on saying that camera had moved
// to recently this value seems to work well -BC
if (motortimer.elapsed() > time)
return true;
else
return false;
}
-------------------------------------------

Anyone know what I'm doing wrong?

[fluffington]

Edit: never mind.

[gborzi]

The problem is that CamState::still is defined in CamState.cpp with a double argument, i.e.bool CamState::still(double time) but it is called without arguments, i.e.csp->still()
Perhaps you forgot to give a default value in the CamState::still declaration ? something like
class CamState {
public:
...
bool still( double time = 0 );
...
};

[joft]

Hi,


../../objdir/FvCartPanel.o(.text+0x3a3c): In function `FvCartPanel::UpdateImage()':
pathcode/fvcart/FvCartPanel.cpp:292: undefined reference to `CamState::still()'
collect2: ld returned 1 exit status


I'd say that you got a linking error here. The linker (ld) isn't able to find the function "CamState::still()".

So you have to add a commandline argument "-l<libname>" which tells the compiler to include the library named <libname> which implements this function.

[nebc]

Thanks for your replies!

It turns out that my code was fine but that I needed to clean my libraries and make them again.

Neb