Parameter packs from the enclosing context can be used unexpanded in a
lambda that is itself part of a pack expansion, but not packs that are part
of the lambda itself. We already check for capture packs; we also need to
check for function parameter packs of the lambda call operator.
Tested x86_64-pc-linux-gnu, applying to trunk.
PR c++/104624
gcc/cp/ChangeLog:
* pt.cc (check_for_bare_parameter_packs): Check for lambda
function parameter pack.
gcc/testsuite/ChangeLog:
* g++.dg/cpp1y/lambda-generic-variadic22.C: New test.
---
gcc/cp/pt.cc | 4 +++-
.../g++.dg/cpp1y/lambda-generic-variadic22.C | 15 +++++++++++++++
2 files changed, 18 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic22.C
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index dde62ee052d..c05783f505f 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -4341,7 +4341,9 @@ check_for_bare_parameter_packs (tree t, location_t loc /*
= UNKNOWN_LOCATION */)
parameter_packs = TREE_CHAIN (parameter_packs))
{
tree pack = TREE_VALUE (parameter_packs);
- if (is_capture_proxy (pack))
+ if (is_capture_proxy (pack)
+ || (TREE_CODE (pack) == PARM_DECL
+ && DECL_CONTEXT (DECL_CONTEXT (pack)) == lam))
break;
}
diff --git a/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic22.C
b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic22.C
new file mode 100644
index 00000000000..670c598a865
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/lambda-generic-variadic22.C
@@ -0,0 +1,15 @@
+// PR c++/104624
+// { dg-do compile { target c++14 } }
+
+template <typename T>
+auto f (T)
+{
+ auto a = [](auto ... i) // { dg-prune-output "incomplete type" }
+ {
+ int x[][i] = { 0 }; // { dg-error "not expanded" }
+ }();
+}
+void g ()
+{
+ f(0);
+}
base-commit: ab91c10792cd3a1ba1495aa30a34ca17b043bafb
--
2.27.0
