06bd74ba4a
The first sentence says: If a template-parameter of a class template, variable template, or alias template has a default template-argument, each subsequent template-parameter shall either have a default template-argument supplied or be a template parameter pack. However, we were only testing for "not a function function template", and referring to an older version of the standard. As far as I can tell, CWG2032 added the variable-template, and the alias-template pre-dates the standard on github. This patch started as a bug fix for #83461 , but ended up fixing a number of similar cases, so those are validated as well.
61 lines
1.8 KiB
C++
61 lines
1.8 KiB
C++
// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
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struct S {
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template<typename Ty = int>
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friend void foo(auto){}
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template<typename Ty = int, typename Tz>
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friend void foo2(){}
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};
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template<typename T>
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struct TemplS {
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template<typename Ty = int>
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friend void foo3(auto){}
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template<typename Ty = int, typename Tz>
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friend void foo4(){}
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};
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void Inst() {
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TemplS<int>();
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}
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// expected-error@+2{{template parameter missing a default argument}}
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// expected-note@+1{{previous default template argument defined here}}
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template<typename T = int, typename U>
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struct ClassTempl{};
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struct HasFriendClassTempl {
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// expected-error@+1{{default template argument not permitted on a friend template}}
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template<typename T = int, typename U>
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friend struct Friend;
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// expected-error@+3{{cannot define a type in a friend declaration}}
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// expected-error@+1{{default template argument not permitted on a friend template}}
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template<typename T = int, typename U>
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friend struct Friend2{};
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};
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template<typename Ty>
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struct HasFriendClassTempl2 {
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// expected-error@+3{{template parameter missing a default argument}}
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// expected-note@+2{{previous default template argument defined here}}
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// expected-note@#INST2{{in instantiation of template class}}
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template<typename T = int, typename U>
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friend struct Friend;
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};
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void Inst2() {
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HasFriendClassTempl2<int>(); // #INST2
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}
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// expected-error@+2{{template parameter missing a default argument}}
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// expected-note@+1{{previous default template argument defined here}}
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template<typename T = int, typename U>
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static constexpr U VarTempl;
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// expected-error@+2{{template parameter missing a default argument}}
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// expected-note@+1{{previous default template argument defined here}}
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template<typename T = int, typename U>
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using TypeAlias = U;
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