[gcc r15-6803] c++: add fixed test [PR118391]

[Marek Polacek via Gcc-cvs]

https://gcc.gnu.org/g:d201715989ce2f110e09cd15246969f9fcae5c61

commit r15-6803-gd201715989ce2f110e09cd15246969f9fcae5c61
Author: Marek Polacek <pola...@redhat.com>
Date:   Fri Jan 10 15:05:00 2025 -0500

    c++: add fixed test [PR118391]
    
    Fixed by r15-6740.
    
            PR c++/118391
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/cpp2a/lambda-uneval20.C: New test.

Diff:
---
 gcc/testsuite/g++.dg/cpp2a/lambda-uneval20.C | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-uneval20.C 
b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval20.C
new file mode 100644
index 000000000000..fa8b504da9db
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval20.C
@@ -0,0 +1,15 @@
+// PR c++/118391
+// { dg-do compile { target c++20 } }
+
+template<typename>
+using A = int;
+
+template<typename T>
+using B = decltype([]<typename> {}.template operator()<T>());
+
+template<typename T>
+using C = A<B<T>>;
+
+C<int> x;
+
+int main() {}