c++: NTTP with array/function type after substitution [PR61355]
We're performing the [temp.param]/10 adjustment at parse time but not
also at substitution time.
PR c++/61355
gcc/cp/ChangeLog:
* pt.c (convert_template_argument): Perform array/function to
pointer conversion on the substituted type of an NTTP.
gcc/testsuite/ChangeLog:
* g++.old-deja/g++.pt/nontype5.C: Adjust.
* g++.dg/template/param6.C: New test.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 1e52aa7..009fe6d 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -8530,6 +8530,10 @@
else
t = tsubst (t, args, complain, in_decl);
+ /* Perform array-to-pointer and function-to-pointer conversion
+ as per [temp.param]/10. */
+ t = type_decays_to (t);
+
if (invalid_nontype_parm_type_p (t, complain))
return error_mark_node;
diff --git a/gcc/testsuite/g++.dg/template/param6.C b/gcc/testsuite/g++.dg/template/param6.C
new file mode 100644
index 0000000..8306e75
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/param6.C
@@ -0,0 +1,32 @@
+// PR c++/61355
+// Verify we perform array-to-pointer and function-to-pointer conversion
+// on the substituted/deduced type of an NTTP.
+
+int f();
+int p[5];
+
+namespace cpp98 {
+ template<class T, T> struct X;
+ typedef X<int(), f> ty1;
+ typedef X<int[5], p> ty2;
+}
+
+namespace cpp11 {
+#if __cpp_variadic_templates
+ template<class T, T...> struct X;
+ using ty1 = X<int(), f>;
+ using ty2 = X<int[5], p>;
+#endif
+}
+
+namespace cpp17 {
+#if __cpp_nontype_template_parameter_auto
+ template<decltype(auto)> struct X;
+ using ty1 = X<f>;
+ using ty2 = X<p>;
+
+ template<decltype(auto)...> struct Y;
+ using ty3 = Y<f>;
+ using ty4 = Y<p>;
+#endif
+}
diff --git a/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C b/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C
index 2678cf7..e24dca4 100644
--- a/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C
+++ b/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C
@@ -19,5 +19,5 @@
int f() { return 0; }
int main() {
-return B<int,&f>::g(); // { dg-error "" } could not convert arg
+return B<int,&f>::g();
}
