diff options
| -rw-r--r-- | gcc/cp/class.cc | 13 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/cond-triv3.C | 44 |
2 files changed, 55 insertions, 2 deletions
diff --git a/gcc/cp/class.cc b/gcc/cp/class.cc index b84f422..aebcb53 100644 --- a/gcc/cp/class.cc +++ b/gcc/cp/class.cc @@ -4795,8 +4795,9 @@ check_methods (tree t) /* Check whether the eligible special member functions (P0848) are user-provided. add_method arranged that the CLASSTYPE_MEMBER_VEC only - has the eligible ones; TYPE_FIELDS also contains ineligible overloads, - which is why this needs to be separate from the loop above. */ + has the eligible ones, unless none are eligible; TYPE_FIELDS also contains + ineligible overloads, which is why this needs to be separate from the loop + above. */ if (tree dtor = CLASSTYPE_DESTRUCTOR (t)) { @@ -4819,6 +4820,10 @@ check_methods (tree t) { if (!user_provided_p (fn)) /* Might be trivial. */; + else if (TREE_CODE (fn) == TEMPLATE_DECL) + /* Templates are never special members. */; + else if (!constraints_satisfied_p (fn)) + /* Not eligible. */; else if (copy_fn_p (fn)) TYPE_HAS_COMPLEX_COPY_CTOR (t) = true; else if (move_fn_p (fn)) @@ -4829,6 +4834,10 @@ check_methods (tree t) { if (!user_provided_p (fn)) /* Might be trivial. */; + else if (TREE_CODE (fn) == TEMPLATE_DECL) + /* Templates are never special members. */; + else if (!constraints_satisfied_p (fn)) + /* Not eligible. */; else if (copy_fn_p (fn)) TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = true; else if (move_fn_p (fn)) diff --git a/gcc/testsuite/g++.dg/cpp2a/cond-triv3.C b/gcc/testsuite/g++.dg/cpp2a/cond-triv3.C new file mode 100644 index 0000000..d0711cf --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/cond-triv3.C @@ -0,0 +1,44 @@ +// { dg-do compile { target c++20 } } + +template<class T> +struct X +{ + T first{}; + + X& operator=(const X&) = delete; + X& operator=(const X&) requires requires (T& t) { t = t; } { return *this; } +}; + +// C++20 std::pair<const int, int>: +using cxx20_pair = X<const int>; +static_assert( __is_trivially_constructible(cxx20_pair, const cxx20_pair&), "" ); +static_assert( !__is_assignable(cxx20_pair&, const cxx20_pair&), "" ); +static_assert( __is_trivially_copyable(cxx20_pair), "" ); + +template<bool, typename, typename F> struct conditional { using type = F; }; +template<typename T, typename F> struct conditional<true, T, F> { using type = T; }; + +struct base +{ + base() = default; + ~base() = default; + base(const base&) = default; + base& operator=(const base&) = delete; +}; + +struct nope; + +template<class T> +struct Y : base +{ + T first{}; + + Y& operator=(typename conditional<__is_assignable(T&, const T&), const Y&, const nope&>::type) + { return *this; } +}; + +// C++17 std::pair<const int, int>: +using cxx17_pair = Y<const int>; +static_assert( __is_trivially_constructible(cxx17_pair, const cxx17_pair&), "" ); +static_assert( ! __is_assignable(cxx17_pair&, const cxx17_pair&), "" ); +static_assert( __is_trivially_copyable(cxx17_pair), "???" ); |