https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120777
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Created attachment 61688 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=61688&action=edit gcc16-pr120777-wip.patch Started playing with this and made some progess, but struct A { int a; constexpr virtual int foo () { return a; }; constexpr A () : a (42) {} constexpr A (int x) : a (x) {} constexpr virtual ~A () { if (a < 42 || a > 62) asm (""); } }; struct B : public A { int b; constexpr virtual int foo () { return a + b; } constexpr B () : A (43), b (42) {} constexpr B (int x, int y) : A (x), b (y) {} constexpr virtual ~B () { if (b < 42 || b > 62) asm (""); } }; struct C : virtual public B { int c; constexpr C () : B (44, 43), c (45) {} constexpr C (int x) : B (44, 43), c (x) {} constexpr virtual int bar () { return a + b + c; } constexpr virtual ~C () { if (c < 42 || c > 62) asm (""); } }; struct D : virtual public B { int d; constexpr D () : B (44, 43), d (45) {} constexpr D (int x) : B (44, 43), d (x) {} constexpr virtual int baz () { return a + b + d; } constexpr virtual ~D () { if (d < 42 || d > 62) asm (""); } }; struct E : public C, D { int e; constexpr E () : B (), C (), D () {} constexpr E (int x, int y, int z, int w, int v) : B (x, y), C (z), D (w), e (v) {} constexpr virtual ~E () { if (e < 42 || e > 62) asm (""); } }; constexpr bool qux () { E f (45, 46, 47, 48, 49); f.a++; f.b++; f.c++; f.d++; f.e++; C *c = static_cast <C *> (&f); D *d = static_cast <D *> (&f); B *b = static_cast <B *> (&f); A *a = static_cast <A *> (&f); if (f.foo () != 46 + 47) return false; if (f.bar () != 46 + 47 + 48) return false; if (f.baz () != 46 + 47 + 49) return false; a->a += 2; b->b += 3; c->c += 4; c->a += 5; d->d += 6; d->a += 7; if (c->foo () != 60 + 50) return false; c->b -= 3; if (d->foo () != 60 + 47) return false; if (f.a != 60 || f.b != 47 || f.c != 52 || f.d != 55 || f.e != 50) return false; return true; } static_assert (qux ()); still doesn't work yet.
