clang/test/SemaCXX/cxx2b-deducing-this-constexpr.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -std=c++2b %s -verify
   2 // expected-no-diagnostics
   3
   4 template <typename Base>
   5 struct Wrap : Base {
   6
   7 };
   8
   9 struct S {
  10     constexpr int f(this const S&) {
  11         return 42;
  12     }
  13     constexpr int f(this const S&, auto&&... args) {
  14         return (args + ... + 0);
  15     }
  16     constexpr int operator[](this const S&) {
  17         return 42;
  18     }
  19     constexpr int operator[](this const S& self, int i) {
  20         return i + self.base;
  21     }
  22     constexpr int operator()(this const S&) {
  23         return 42;
  24     }
  25     constexpr int operator()(this const S& self, int i) {
  26         return self.base + i;
  27     }
  28     constexpr bool operator==(this const S& self, auto && test) {
  29         return self.base == test;
  30     };
  31     constexpr int operator*(this const S& self) {
  32         return self.base + 22;
  33     };
  34     constexpr operator Wrap<S> (this const S& self) {
  35         return Wrap<S>{self};
  36     };
  37     constexpr int operator <<(this Wrap<S> self, int i) {
  38         return self.base+i;
  39     }
  40
  41     int base = 20;
  42 };
  43
  44 consteval void test() {
  45     constexpr S s;
  46     static_assert(s.f() == 42);
  47     static_assert(s[] == 42);
  48     static_assert(s[22] == 42);
  49     static_assert(s.f() == 42);
  50     static_assert(s() == 42);
  51     static_assert(s(22) == 42);
  52     static_assert(s == 20);
  53     static_assert(s != 0);
  54     static_assert(*s == 42);
  55     static_assert((s << 11) == 31);
  56 }
  57
  58 namespace GH68070 {
  59
  60 constexpr auto f = [x = 3]<typename Self>(this Self&& self) {
  61     return x;
  62 };
  63
  64 auto g = [x = 3]<typename Self>(this Self&& self) {
  65     return x;
  66 };
  67
  68 int test() {
  69   constexpr int a = f();
  70   static_assert(a == 3);
  71   return f() + g();
  72 }
  73
  74 }