gcc/testsuite/g++.dg/template/error45.C

   1 // Contributed by Dodji Seketeli <dodji@redhat.com>
   2 // Origin PR c++/42634
   3 // { dg-options "-g -std=gnu++0x" }
   4 // { dg-do compile }
   5
   6 template<typename T> T declval();
   7
   8 template<typename T, typename... Args> struct is_constructible {
   9     template<typename T1, typename... Args1> static decltype(T1(declval<Args1>()...), char()) test();
  10     static const bool value = sizeof(test<T, Args...>()) == 1;
  11 };
  12 template<bool> struct enable_if {
  13         typedef void type;
  14 };
  15 template<class T1, class T2> struct pair {
  16     template<class U2,
  17              class = typename enable_if<is_constructible<T2,U2&&>::value>::type
  18              >
  19     pair(const T1&, U2&&) { }
  20 };
  21 struct string {
  22   string() : p(0) {}
  23   char* p;
  24 };
  25
  26 struct Foo {
  27   string s;
  28   int i;
  29 };
  30
  31 void f()
  32 {
  33   pair<int, Foo>(1, Foo());
  34 }
  35