clang/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p8.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
   2
   3 using size_t = decltype(sizeof(int));
   4
   5 struct S {
   6   constexpr int f(); // expected-warning {{C++14}}
   7   constexpr int g() const;
   8   constexpr int h(); // expected-warning {{C++14}}
   9   int h();
  10   static constexpr int Sf();
  11   /*static*/ constexpr void *operator new(size_t) noexcept;
  12   template<typename T> constexpr T tm(); // expected-warning {{C++14}}
  13   template<typename T> static constexpr T ts();
  14 };
  15
  16 void f(const S &s) {
  17   s.f();
  18   s.g();
  19
  20   int (*Sf)() = &S::Sf;
  21   int (S::*f)() const = &S::f;
  22   int (S::*g)() const = &S::g;
  23   void *(*opNew)(size_t) = &S::operator new;
  24   int (S::*tm)() const = &S::tm;
  25   int (*ts)() = &S::ts;
  26 }
  27
  28 constexpr int S::f() const { return 0; }
  29 constexpr int S::g() { return 1; } // expected-warning {{C++14}}
  30 constexpr int S::h() { return 0; } // expected-warning {{C++14}}
  31 int S::h() { return 0; }
  32 constexpr int S::Sf() { return 2; }
  33 constexpr void *S::operator new(size_t) noexcept { return 0; }
  34 template<typename T> constexpr T S::tm() { return T(); } // expected-warning {{C++14}}
  35 template<typename T> constexpr T S::ts() { return T(); }
  36
  37 namespace std_example {
  38
  39   class debug_flag {
  40   public:
  41     explicit debug_flag(bool);
  42     constexpr bool is_on() const; // ok (dr1684)
  43   private:
  44     bool flag;
  45   };
  46
  47   constexpr int bar(int x, int y) // expected-note {{here}}
  48     { return x + y + x*y; }
  49   int bar(int x, int y) // expected-error {{non-constexpr declaration of 'bar' follows constexpr declaration}}
  50     { return x * 2 + 3 * y; }
  51
  52 }
  53
  54 // The constexpr specifier is allowed for static member functions of non-literal types.
  55 class NonLiteralClass {
  56   NonLiteralClass(bool);
  57   static constexpr bool isDebugFlag();
  58 };