llvm-project/clang/test/SemaTemplate/default-arguments.cpp

124 lines
3.4 KiB
C++

// RUN: clang-cc -fsyntax-only -verify %s
template<typename T, int N = 2> struct X; // expected-note{{template is declared here}}
X<int, 1> *x1;
X<int> *x2;
X<> *x3; // expected-error{{too few template arguments for class template 'X'}}
template<typename U = float, int M> struct X;
X<> *x4;
template<typename T = int> struct Z { };
template struct Z<>;
// PR4362
template<class T> struct a { };
template<> struct a<int> { static const bool v = true; };
template<class T, bool = a<T>::v> struct p { }; // expected-error {{no member named 'v'}}
template struct p<bool>; // expected-note {{in instantiation of default argument for 'p<bool>' required here}}
template struct p<int>;
// PR5187
template<typename T, typename U>
struct A;
template<typename T, typename U = T>
struct A;
template<typename T, typename U>
struct A {
void f(A<T>);
};
template<typename T>
struct B { };
template<>
struct B<void> {
typedef B<void*> type;
};
// Nested default arguments for template parameters.
template<typename T> struct X1 { };
template<typename T>
struct X2 {
template<typename U = typename X1<T>::type> // expected-error{{no type named}}
struct Inner1 { };
template<T Value = X1<T>::value> // expected-error{{no member named 'value'}}
struct NonType1 { };
template<T Value>
struct Inner2 { };
template<typename U>
struct Inner3 {
template<typename X = T, typename V = U>
struct VeryInner { };
template<T Value1 = sizeof(T), T Value2 = sizeof(U),
T Value3 = Value1 + Value2>
struct NonType2 { };
};
};
X2<int> x2i;
X2<int>::Inner1<float> x2iif;
X2<int>::Inner1<> x2bad; // expected-note{{instantiation of default argument}}
X2<int>::NonType1<'a'> x2_nontype1;
X2<int>::NonType1<> x2_nontype1_bad; // expected-note{{instantiation of default argument}}
// Check multi-level substitution into template type arguments
X2<int>::Inner3<float>::VeryInner<> vi;
X2<char>::Inner3<int>::NonType2<> x2_deep_nontype;
template<typename T, typename U>
struct is_same { static const bool value = false; };
template<typename T>
struct is_same<T, T> { static const bool value = true; };
int array1[is_same<__typeof__(vi),
X2<int>::Inner3<float>::VeryInner<int, float> >::value? 1 : -1];
int array2[is_same<__typeof(x2_deep_nontype),
X2<char>::Inner3<int>::NonType2<sizeof(char), sizeof(int),
sizeof(char)+sizeof(int)> >::value? 1 : -1];
// Template template parameter defaults
template<template<typename T> class X = X2> struct X3 { };
int array3[is_same<X3<>, X3<X2> >::value? 1 : -1];
struct add_pointer {
template<typename T>
struct apply {
typedef T* type;
};
};
template<typename T, template<typename> class X = T::template apply>
struct X4;
int array4[is_same<X4<add_pointer>,
X4<add_pointer, add_pointer::apply> >::value? 1 : -1];
template<int> struct X5 {}; // expected-note{{has a different type 'int'}}
template<long> struct X5b {};
template<typename T,
template<T> class B = X5> // expected-error{{template template argument has different}} \
// expected-note{{previous non-type template parameter}}
struct X6 {};
X6<int> x6a;
X6<long> x6b; // expected-note{{while checking a default template argument}}
X6<long, X5b> x6c;
template<template<class> class X = B<int> > struct X7; // expected-error{{must be a class template}}