clang/test/SemaTemplate/instantiate-var-template.cpp

   1 // RUN: %clang_cc1 -verify -std=c++1y %s
   2
   3 namespace PR17846 {
   4   template <typename T> constexpr T pi = T(3.14);
   5   template <typename T> constexpr T tau = 2 * pi<T>;
   6   constexpr double tau_double = tau<double>;
   7   static_assert(tau_double == 6.28, "");
   8 }
   9
  10 namespace PR17848 {
  11   template<typename T> constexpr T var = 12345;
  12   template<typename T> constexpr T f() { return var<T>; }
  13   constexpr int k = f<int>();
  14   static_assert(k == 12345, "");
  15 }
  16
  17 namespace NonDependent {
  18   template<typename T> constexpr T a = 0;
  19   template<typename T> constexpr T b = a<int>;
  20   static_assert(b<int> == 0, "");
  21 }
  22
  23 namespace InstantiationDependent {
  24   int f(int);
  25   void f(char);
  26
  27   template<int> constexpr int a = 1;
  28   template<typename T> constexpr T b = a<sizeof(sizeof(f(T())))>; // expected-error {{invalid application of 'sizeof' to an incomplete type 'void'}}
  29
  30   static_assert(b<int> == 1, "");
  31   static_assert(b<char> == 1, ""); // expected-note {{in instantiation of}}
  32
  33   template<typename T> void f() {
  34     int check[a<sizeof(sizeof(f(T())))> == 0 ? 1 : -1]; // expected-error {{array with a negative size}}
  35   }
  36 }
  37
  38 namespace PR24483 {
  39   template<typename> struct A;
  40   template<typename... T> A<T...> models;
  41   template<> struct B models<>; // expected-error {{incomplete type 'struct B'}} expected-note {{forward declaration}}
  42 }
  43
  44 namespace InvalidInsertPos {
  45   template<typename T, int N> T v;
  46   template<int N> decltype(v<int, N-1>) v<int, N>;
  47   template<> int v<int, 0>;
  48   int k = v<int, 500>;
  49 }