The following code compiles in Clang 3.3, but not GCC 4.8.2:


//---------------------------------------
// g++ -std=c++11 -Wall -Wextra -pedantic 

void f() {}

static constexpr void (*g1)() = &f; // ok
static constexpr void (*g2)() = f; // ok
struct S {
    static constexpr void (*g3)() = &f; // ok
    static constexpr void (*g4)() = f; // error: field initializer is not constant
};

//---------------------------------------