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#include <iostream>
#include <string>
 
using std::cout;
using std::endl;
 
#define PFN(x) cout << x << __PRETTY_FUNCTION__ << endl
#define PF     PFN("")
#define NL     cout << endl
 
struct A {
    constexpr A() { PF; }
    virtual ~A() { PF; NL; }
};
 
struct B : A {
    constexpr B() { PFN(" "); }
    virtual ~B() { PFN(" "); }
};
 
int main(int argc, char** argv) {
    { A a; }
    { B b; }
    A* a = new B;
    delete a;
    return 0;
}

prog.cpp:12:15: error: constexpr constructor never produces a constant expression [-Winvalid-constexpr]
    constexpr A() { PF; }
              ^
prog.cpp:12:21: note: non-constexpr function 'operator<<<std::char_traits<char> >' cannot be used in a constant expression
    constexpr A() { PF; }
                    ^
prog.cpp:8:16: note: expanded from macro 'PF'
#define PF     PFN("")
               ^
prog.cpp:7:26: note: expanded from macro 'PFN'
#define PFN(x) cout << x << __PRETTY_FUNCTION__ << endl
                         ^
/usr/bin/../lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/ostream:556:5: note: declared here
    operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
    ^
1 error generated.

Standard output is empty