linking template metaprogramming issue with g++ - templates

Question

I am porting some windows code that compiles like would expect under msvc 10, but I am having trouble with it linking under g++ 4.8 and/or clang 3.5.
masks.h
#ifndef MASKS_H
#define MASKS_H
#include <boost/array.hpp>
#include <boost/assign/list_of.hpp>
#include <boost/preprocessor/repetition/repeat.hpp>
namespace MASKS
{
// ------------------------------------------------- power function
template<class TYPE, uint32_t Base, uint32_t Power>
struct Pow
{
static const TYPE tmp = Pow<TYPE, Base, Power / 2>::value;
static const TYPE value = (Power % 2 == 0) ? (tmp * tmp) : (Base * tmp * tmp);
};
template<class TYPE, uint32_t Base>
struct Pow<TYPE, Base, 0>
{
static const TYPE value = 1;
};
template<class TYPE, uint32_t Base>
struct Pow<TYPE, Base, 1>
{
static const TYPE value = Base;
};
// ------------------------------------------------- mask function
template<class TYPE, int Val>
struct Mask
{
static const TYPE value = Pow<TYPE, 2, Val>::value - 1;
};
template<class TYPE>
struct Mask<TYPE, 64>
{
static const TYPE value = 0xffffffffffffffff;
};
//#define MASK(z, n, text) (MASKS::Mask<uint64_t, n>::value)
static const boost::array<uint64_t, 4> s_Masks =
boost::assign::list_of<uint64_t>
(MASKS::Mask<uint64_t, 0>::value)
(MASKS::Mask<uint64_t, 1>::value)
(MASKS::Mask<uint64_t, 2>::value)
(MASKS::Mask<uint64_t, 3>::value)
//BOOST_PP_REPEAT_FROM_TO (0, 65, MASK, text)
;
inline uint64_t GetMask (size_t iLen) { return MASKS::s_Masks[iLen]; }
} // namespace MASKS
#endif // MASKS_H
main.c
#include <iostream>
#include "masks.h"
int main (int /*argc*/, char */*argv*/[])
{
std::cout << "63 bit mask: " << std::hex << std::showbase << MASKS::GetMask (63) << std::endl;
return 0;
}
When I compile it will not link and gives the following error:
g++ masks.cpp -o mask -std=c++11 -pedantic -Wall -Wextra
tmp/ccYZ0MMb.o: In function `__static_initialization_and_destruction_0(int, int)':
masks.cpp:(.text+0xd9): undefined reference to `MASKS::Mask<unsigned long long, 0>::value'
masks.cpp:(.text+0xea): undefined reference to `MASKS::Mask<unsigned long long, 1>::value'
masks.cpp:(.text+0xfe): undefined reference to `MASKS::Mask<unsigned long long, 2>::value'
masks.cpp:(.text+0x10f): undefined reference to `MASKS::Mask<unsigned long long, 3>::value'
collect2: error: ld returned 1 exit status
I am not sure what I am forgetting here. I expected the TMP objects/functions to get translated to values by the compiler and stored in the array of masks I am trying to build. I am rusty on my g++ syntax I guess. Can anyone see what I've done wrong?
Thanks.