[gcc r16-3444] c++: > in lambda in template arg [PR107953]

[Jason Merrill via Gcc-cvs]

https://gcc.gnu.org/g:00e8690ef0d7ac1ced87ceee309dbfa27909a35c

commit r16-3444-g00e8690ef0d7ac1ced87ceee309dbfa27909a35c
Author: Jason Merrill <ja...@redhat.com>
Date:   Sun Aug 24 05:15:01 2025 -0400

    c++: > in lambda in template arg [PR107953]
    
    As with PR116928, we need to set greater_than_is_operator_p within the
    lambda delimiters.
    
            PR c++/107953
    
    gcc/cp/ChangeLog:
    
            * parser.cc (cp_parser_lambda_expression): Set
            greater_than_is_operator_p.
    
    gcc/testsuite/ChangeLog:
    
            * g++.dg/cpp2a/lambda-targ18.C: New test.

Diff:
---
 gcc/cp/parser.cc                           |  2 ++
 gcc/testsuite/g++.dg/cpp2a/lambda-targ18.C | 13 +++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 0d45ab427992..9f9bd5650047 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -11806,6 +11806,8 @@ cp_parser_lambda_expression (cp_parser* parser,
      it now.  */
   push_deferring_access_checks (dk_no_deferred);
 
+  auto gr = make_temp_override (parser->greater_than_is_operator_p, true);
+
   if (!consteval_block_p)
     {
       cp_parser_lambda_introducer (parser, lambda_expr);
diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-targ18.C 
b/gcc/testsuite/g++.dg/cpp2a/lambda-targ18.C
new file mode 100644
index 000000000000..d4011f3e315f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-targ18.C
@@ -0,0 +1,13 @@
+// PR c++/107953
+// { dg-do compile { target c++20 } }
+
+template<auto F>
+struct Foo {};
+
+Foo<[](){ return 1 >= 0; }> foo1{};
+
+Foo<[](){ return (1 > 0); }> foo2{};
+
+Foo<[](){ return 1 > 0; }> foo3{};
+
+Foo<[g = 1 > 0]{ return g; }> foo4{};