1 // P1064R0
2 // { dg-do compile }
3 // { dg-options "-std=c++2a" }
4 
5 struct X1
6 {
7   virtual int f() const = 0;
8   virtual int f(int) const = 0;
9   virtual int f(int, int) const = 0;
10 };
11 
12 struct X2: public X1
13 {
fX214   constexpr virtual int f() const { return 2; }
fX215   constexpr virtual int f(int) const { return 12; }
fX216   constexpr virtual int f(int, int) const { return 22; }
17 };
18 
19 struct X3: public X2
20 {
fX321   virtual int f() const { return 3; }
fX322   virtual int f(int) const { return 13; }
fX323   virtual int f(int, int) const { return 23; }
24 };
25 
26 struct X4: public X3
27 {
fX428   constexpr virtual int f() const { return 4; }
fX429   constexpr virtual int f(int) const { return 14; }
fX430   constexpr virtual int f(int, int) const { return 24; }
31 };
32 
33 constexpr int (X1::*pf)() const = &X1::f;
34 constexpr int (X1::*pf1)(int) const = &X1::f;
35 constexpr int (X1::*pf2)(int, int) const = &X1::f;
36 
37 constexpr X2 x2;
38 static_assert(x2.f() == 2);
39 static_assert((x2.*pf)() == 2);
40 static_assert(x2.f(1) == 12);
41 static_assert((x2.*pf1)(1) == 12);
42 static_assert(x2.f(1, 2) == 22);
43 static_assert((x2.*pf2)(1, 2) == 22);
44 
45 constexpr X1 const& r2 = x2;
46 static_assert(r2.f() == 2);
47 static_assert((r2.*pf)() == 2);
48 static_assert(r2.f(1) == 12);
49 static_assert((r2.*pf1)(1) == 12);
50 static_assert(r2.f(1, 2) == 22);
51 static_assert((r2.*pf2)(1, 2) == 22);
52 
53 constexpr X1 const* p2 = &x2;
54 static_assert(p2->f() == 2);
55 static_assert((p2->*pf)() == 2);
56 static_assert(p2->f(1) == 12);
57 static_assert((p2->*pf1)(1) == 12);
58 static_assert(p2->f(1, 2) == 22);
59 static_assert((p2->*pf2)(1, 2) == 22);
60 
61 constexpr X4 x4;
62 static_assert(x4.f() == 4);
63 static_assert((x4.*pf)() == 4);
64 static_assert(x4.f(1) == 14);
65 static_assert((x4.*pf1)(1) == 14);
66 static_assert(x4.f(1, 2) == 24);
67 static_assert((x4.*pf2)(1, 2) == 24);
68 
69 constexpr X1 const& r4 = x4;
70 static_assert(r4.f() == 4);
71 static_assert((r4.*pf)() == 4);
72 static_assert(r4.f(1) == 14);
73 static_assert((r4.*pf1)(1) == 14);
74 static_assert(r4.f(1, 2) == 24);
75 static_assert((r4.*pf2)(1, 2) == 24);
76 
77 constexpr X1 const* p4 = &x4;
78 static_assert(p4->f() == 4);
79 static_assert((p4->*pf)() == 4);
80 static_assert(p4->f(1) == 14);
81 static_assert((p4->*pf1)(1) == 14);
82 static_assert(p4->f(1, 2) == 24);
83 static_assert((p4->*pf2)(1, 2) == 24);
84