Template specialization for an empty parameter pack

I have a variadic template function which calls itself to determine the largest number in a list (constituted by the templatized arguments). I am trying to make a specialization for when the parameter pack is empty so I can just return the number at the front of the list, but I don't know how to do that. I am just becoming familiar with variadic templates and template specialization, but this is what I have so far:

#include <string>
#include <iostream>

using namespace std;

template <int N, int... N2>
int tmax() {
    return N > tmax<N2...>() ? N : tmax<N2...>();
}

template <int N>
int tmax() {
    return N;
}

int main() {
    cout << tmax<32, 43, 54, 12, 23, 34>();
}

However, this produces the following error:

test.cpp: In function ‘int tmax() [with int N = 34, int ...N2 = {}]’:
test.cpp:9:45:   instantiated from ‘int tmax() [with int N = 23, int ...N2 = {34}]’
test.cpp:9:45:   instantiated from ‘int tmax() [with int N = 12, int ...N2 = {23, 34}]’
test.cpp:9:45:   instantiated from ‘int tmax() [with int N = 54, int ...N2 = {12, 23, 34}]’
test.cpp:9:45:   instantiated from ‘int tmax() [with int N = 43, int ...N2 = {54, 12, 23, 34}]’
test.cpp:9:45:   instantiated from ‘int tmax() [with int N = 32, int ...N2 = {43, 54, 12, 23, 34}]’
test.cpp:18:39:   instantiated from here
test.cpp:9:45: error: no matching function for call to ‘tmax()’
test.cpp:9:45: error: no matching function for call to ‘tmax()’

I have also tried this, just to see if it would work (although it introduces the number 0 to the list randomly so that it can't ever return a number less than 0):

template <int N, int... N2>
int tmax() {
    return N > tmax<N2...>() ? N : tmax<N2...>();
}

template <>
int tmax<>() {
    return 0;
}

However, in addition to the errors mentioned above, I get this error:

error: template-id ‘tmax<>’ for ‘int tmax()’ does not match any template declaration

So what should I do to get this working?

I am using g++ 4.5.2 with the -std=c++0x flag.