c++ template class member function specialization

I have a problem where I want to specialize a template member function of a template class in the code below. The answer to this question explicit specialization of template class member function seems to suggest that it can't be done. Is that correct, and if so, is there any work around I can use so that by inline inc functions get expanded at compile time?

Many thanks!

#include 
#include 


template 
struct IdxIterator {
private:
  int startIdx[N], endIdx[N];  
  int curIdx[N];
  IT iter;

public:
  IdxIterator(IT it, int cur[], int start[], int end[]): iter(it) {

    for (int i = 0; i < N; i++) {
      curIdx[i] = cur[i];
      startIdx[i] = start[i];
      endIdx[i] = end[i];
    }
  }

  template 
  inline void inc() {
    curIdx[dim]++;

    if (curIdx[dim] > endIdx[dim]) {
      if (dim > 0) {
        curIdx[dim] = startIdx[dim];
        inc();
      }
    }
  }

  // how to declare this specialization?
  template <> template <>

  inline void inc<-1>() {
    std::cerr << "IdxIterator::inc(" << -1 << ") dim out of bounds!\n";
    throw 1;
  }

  inline IdxIterator operator++() {
    iter++;
    inc();
    return *this;
  }


};

int main(int argc, char** argv) {

  int *buf = new int[100];
  int start[1], end[1];
  start[0] = 0; end[0] = 99;
  IdxIterator it(buf, start, start, end);
  ++it;


  return 0;

}

G++ spits out:

test2.cpp:32:13: error: explicit specialisation in non-namespace scope

‘struct IdxIterator’ test2.cpp:32:25: error: explicit
specialisation in non-namespace scope ‘struct IdxIterator’
test2.cpp:33:23: error: template-id ‘inc<-0x00000000000000001>’ in
declaration of primary template test2.cpp: In member function ‘void
IdxIterator::inc() [with int dim = -0x000000000000003fe, IT =
int*, unsigned int N = 1u]’: test2.cpp:27:9: error: template
instantiation depth exceeds maximum of 1024 (use -ftemplate-depth= to
increase the maximum) instantiating ‘void IdxIterator::inc()
[with int dim = -0x000000000000003ff, IT = int*, unsigned int N = 1u]’
test2.cpp:27:9: recursively instantiated from ‘void IdxIterator::inc() [with int dim = -0x00000000000000001, IT = int*, unsigned

int N = 1u]’ test2.cpp:27:9: instantiated from ‘void IdxIterator::inc() [with int dim = 0, IT = int*, unsigned int N = 1u]’
test2.cpp:41:5: instantiated from ‘IdxIterator
IdxIterator::operator++() [with IT = int*, unsigned int N =
1u]’ test2.cpp:53:5: instantiated from here

test2.cpp: At global scope: test2.cpp:22:15: warning: inline function
‘void IdxIterator::inc() [with int dim = -0x000000000000003ff,
IT = int*, unsigned int N = 1u]’ used but never defined [enabled by
default]