Tested x86_64-pc-linux-gnu, applying to trunk. -- >8 -- We used to hit the "Error reporting routines re-entered." ICE here but it was fixed by Patrick's r14-3809.
PR c++/100557 gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-pr100557.C: New test. --- .../g++.dg/cpp2a/concepts-pr100557.C | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-pr100557.C diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr100557.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr100557.C new file mode 100644 index 00000000000..8dcd0eaca51 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-pr100557.C @@ -0,0 +1,21 @@ +// PR c++/100557 +// { dg-do compile { target c++20 } } + +template <typename _Tp> _Tp declval(); + +struct print_tag_; + +bool tag_invoke(print_tag_, auto); +bool tag_invoke(print_tag_, auto obj) requires requires { *obj; }; + +template <typename CPO, typename... Args> +auto try_tag_invoke() noexcept(tag_invoke(declval<CPO>, declval<Args>()...)) // { dg-error "no matching function for call" } + -> decltype(tag_invoke(CPO(), declval<Args>()...)); + +struct print_tag_ { + void operator()(auto... args) noexcept(noexcept( try_tag_invoke<print_tag_, decltype(args)...>())); +} print; + +void foo() { + print(0); +} base-commit: 2f47ca046eecf8f2fcae23df3ccee44d943ef512 -- 2.44.0