[gcc r14-9674] c++: add fixed test [PR100557]

[Marek Polacek via Gcc-cvs]

https://gcc.gnu.org/g:c0e199e4dbe652cd16d7248f0bfe166540f5d95b

commit r14-9674-gc0e199e4dbe652cd16d7248f0bfe166540f5d95b
Author: Marek Polacek <pola...@redhat.com>
Date:   Tue Mar 26 10:39:48 2024 -0400

    c++: add fixed test [PR100557]
    
    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.

Diff:
---
 gcc/testsuite/g++.dg/cpp2a/concepts-pr100557.C | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

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);
+}