While looking at PR105964 I noticed that we were unnecessarily repeating
the deduction loop because of seeing a non-type parameter with type 'auto'.
It is indeed dependent, but not on any other deductions.
Tested x86_64-pc-linux-gnu, applying to trunk.
gcc/cp/ChangeLog:
* pt.cc (type_unification_real): An auto tparm can't
be affected by other deductions.
---
gcc/cp/pt.cc | 2 ++
1 file changed, 2 insertions(+)
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 4d1c325432d..80d2bec2348 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -22982,6 +22982,7 @@ type_unification_real (tree tparms,
deduced from a later argument than the one from which
this parameter can be deduced. */
if (TREE_CODE (tparm) == PARM_DECL
+ && !is_auto (TREE_TYPE (tparm))
&& uses_template_parms (TREE_TYPE (tparm))
&& saw_undeduced < 2)
{
@@ -23042,6 +23043,7 @@ type_unification_real (tree tparms,
if (saw_undeduced == 1
&& TREE_CODE (parm) == PARM_DECL
+ && !is_auto (TREE_TYPE (parm))
&& uses_template_parms (TREE_TYPE (parm)))
{
/* The type of this non-type parameter depends on undeduced
base-commit: 349a39f061407ce2339d2ba25da97005f2030c88
prerequisite-patch-id: d5622f522428b601200c8c234ddb5e58c91dcb06
--
2.27.0
