The following code is accepted by clang 3.2, but causes 3.0 to crash. Gcc 4.7 and 4.8 emit undefined references.

#include <iostream>

template< size_t k > struct Mod {
    int i;

    static Mod div0(int x,int y){ return x/y; }

    typedef Mod(*func1)(int,int);
    static func1 div1;

    constexpr Mod( int i ) : i(i) { }

    constexpr operator int () { return i; }
};

typedef int(*ii2i)(int,int);

template< size_t k >
typename Mod<k>::func1 Mod<k>::div1 = []( int x, int y ) { return Mod<k>(x / y); };

// Ok
//Mod<3> div3( int x, int y ) { return x/y; }
//template< size_t k >
//typename Mod<k>::func1 Mod<k>::div1 = div3;

template struct Mod<3>;
int main() {
    std::cout << Mod<3>::div0(10,2) << std::endl;
    std::cout << Mod<3>::div1(10,2) << std::endl; // undefined
}

version:
$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.2-5ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --disable-werror --with-arch-32=i686 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-5ubuntu1)