clang/test/SemaTemplate/function-template-specialization.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2
   3 template <int N>
   4 void f0(int (&array)[N]); // expected-note {{candidate template ignored: could not match 'int' against 'char'}}
   5
   6 // Simple function template specialization (using overloading)
   7 template<> void f0(int (&array)[1]);
   8
   9 void test_f0() {
  10   int iarr1[1];
  11   f0(iarr1);
  12 }
  13
  14 // Function template specialization where there are no matches
  15 template<> void f0(char (&array)[1]); // expected-error{{no function template matches}}
  16 template<> void f0<2>(int (&array)[2]) { }
  17
  18 // Function template specialization that requires partial ordering
  19 template<typename T, int N> void f1(T (&array)[N]); // expected-note{{matches}}
  20 template<int N> void f1(int (&array)[N]); // expected-note{{matches}}
  21
  22 template<> void f1(float (&array)[1]);
  23 template<> void f1(int (&array)[1]);
  24
  25 // Function template specialization that results in an ambiguity
  26 template<typename T> void f1(T (&array)[17]); // expected-note{{matches}}
  27 template<> void f1(int (&array)[17]); // expected-error{{ambiguous}}
  28
  29 // Resolving that ambiguity with explicitly-specified template arguments.
  30 template<int N> void f2(double (&array)[N]);
  31 template<typename T> void f2(T (&array)[42]);
  32
  33 template<> void f2<double>(double (&array)[42]);
  34 template<> void f2<42>(double (&array)[42]);
  35
  36 void f2<25>(double (&array)[25]); // expected-error{{specialization}}
  37
  38 // PR5833
  39 namespace PR5833 {
  40   template <typename T> bool f0(T &t1);
  41   template <> bool f0<float>(float &t1);
  42 }
  43 template <> bool PR5833::f0<float>(float &t1) {}
  44
  45 // PR8295
  46 namespace PR8295 {
  47   template <typename T> void f(T t) {}
  48   template <typename T> void f<T*>(T* t) {} // expected-error{{function template partial specialization is not allowed}}
  49 }
  50
  51 class Foo {
  52   template<class T>
  53   static void Bar(const T& input);
  54
  55   // Don't crash here.
  56   template<>
  57   static void Bar(const long& input) {}  // expected-warning{{explicit specialization cannot have a storage class}}
  58 };