Linker / template class problem

[Anonymous]

Have this error -
z:\c++\prog\main.o(.text$__8progi+0x23):main.cpp: undefined reference to `sac<int>::sac(int)'

Have two cpp files, main and sac
Have one header for sac

Compiles OK, but Linker gives above error

I know what causes error, but don't know how to fix

sac is a very simple template
template <class Dtype> sac {
public:
sac( int size ) ;
// rest of definition
};

main creates object {
sac<int> list(100);
}

And when I compile I get above error

However, if I put definition of sac::sac(int)
within class, all is ok
But if template <class Dtype> sac<Dtype>::sac(int)
is in sac.cpp, I get the error from the linker

This doesn't seem to happen with ordinary classes
just templates

I can fix this error by placing #include "sac.cpp"
at start of main.cpp - but then the code for sac.cpp is being compiled with main.cpp code

Any ideas on how to fix ?

[Anonymous]

why cant you just always include #include "sac.cpp" if that fixes it?

(just an idea, i really have no idea what this program means or does)