1 // PR c++/89833
2 // Test to verify that arrays of null pointer to members used as
3 // non-type template arguments are interprested as null regardless
4 // of the form of their initialization.
5 // { dg-do compile { target c++2a } }
6 // { dg-options "-O2 -Wall -fdump-tree-optimized" }
7 
8 struct A { int i; };
9 
10 typedef int A::*pam_t;
11 
12 struct B { pam_t a[2]; };
13 template <B x> struct C { static constexpr B b = x; };
14 
f__()15 B f__   () { return B{ }; }
f0_()16 B f0_   () { return B{ 0 }; }
f00()17 B f00   () { return B{ 0, 0 }; }
18 
19 typedef C<B{ }>      X__;
20 typedef C<B{ 0 }>    X0_;
21 typedef C<B{ 0, 0 }> X00;
22 
g__()23 B g__ () { return X__::b; }
g0_()24 B g0_ () { return X0_::b; }
g00()25 B g00 () { return X00::b; }
26 
27 const B b__{ };
28 const B b0_{ 0 };
29 const B b00{ 0, 0 };
30 
31 const pam_t apam__[2] = { };
32 const pam_t apam0_[2] = { 0 };
33 const pam_t apam00[2] = { 0, 0 };
34 
35 #define assert(expr) \
36   (expr) ? (void)0 : __builtin_abort ()
37 
test()38 void test ()
39 {
40   assert (f__ ().a[0] == nullptr && f__ ().a[1] == nullptr);
41   assert (f0_ ().a[0] == nullptr && f0_ ().a[1] == nullptr);
42   assert (f00 ().a[0] == nullptr && f00 ().a[1] == nullptr);
43 
44   assert (g__ ().a[0] == nullptr && g__ ().a[1] == nullptr);
45   assert (g0_ ().a[0] == nullptr && g0_ ().a[1] == nullptr);
46   assert (g00 ().a[0] == nullptr && g00 ().a[1] == nullptr);
47 
48   assert (b__.a[0] == nullptr && b__.a[1] == nullptr);
49   assert (b0_.a[0] == nullptr && b0_.a[1] == nullptr);
50   assert (b00.a[0] == nullptr && b00.a[1] == nullptr);
51 
52   assert (apam__[0] == nullptr && apam__[1] == nullptr);
53   assert (apam0_[0] == nullptr && apam0_[1] == nullptr);
54   assert (apam00[0] == nullptr && apam00[1] == nullptr);
55 }
56 
57 // { dg-final { scan-tree-dump-not "abort" "optimized" } }
58