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

   1 // RUN: %clang_cc1 -fsyntax-only -std=c++2b %s -verify
   2 // RUN: %clang_cc1 -fsyntax-only -std=c++2b %s -verify -fexperimental-new-constant-interpreter
   3 // expected-no-diagnostics
   4
   5 template <typename Base>
   6 struct Wrap : Base {
   7
   8 };
   9
  10 struct S {
  11     constexpr int f(this const S&) {
  12         return 42;
  13     }
  14     constexpr int f(this const S&, auto&&... args) {
  15         return (args + ... + 0);
  16     }
  17     constexpr int operator[](this const S&) {
  18         return 42;
  19     }
  20     constexpr int operator[](this const S& self, int i) {
  21         return i + self.base;
  22     }
  23     constexpr int operator()(this const S&) {
  24         return 42;
  25     }
  26     constexpr int operator()(this const S& self, int i) {
  27         return self.base + i;
  28     }
  29     constexpr bool operator==(this const S& self, auto && test) {
  30         return self.base == test;
  31     };
  32     constexpr int operator*(this const S& self) {
  33         return self.base + 22;
  34     };
  35     constexpr operator Wrap<S> (this const S& self) {
  36         return Wrap<S>{self};
  37     };
  38     constexpr int operator <<(this Wrap<S> self, int i) {
  39         return self.base+i;
  40     }
  41
  42     int base = 20;
  43 };
  44
  45 consteval void test() {
  46     constexpr S s;
  47     static_assert(s.f() == 42);
  48     static_assert(s[] == 42);
  49     static_assert(s[22] == 42);
  50     static_assert(s.f() == 42);
  51     static_assert(s() == 42);
  52     static_assert(s(22) == 42);
  53     static_assert(s == 20);
  54     static_assert(s != 0);
  55     static_assert(*s == 42);
  56     static_assert((s << 11) == 31);
  57 }
  58
  59 namespace GH68070 {
  60
  61 constexpr auto f = [x = 3]<typename Self>(this Self&& self) {
  62     return x;
  63 };
  64
  65 auto g = [x = 3]<typename Self>(this Self&& self) {
  66     return x;
  67 };
  68
  69 int test() {
  70   constexpr int a = f();
  71   static_assert(a == 3);
  72   return f() + g();
  73 }
  74
  75 }