Here ever since r12-6022-gbb2a7f80a98de3 we stopped deeming the partial specialization #2 to be more specialized than #1 ultimately because dependent operator expressions now have a DEPENDENT_OPERATOR_TYPE type instead of an empty type, and this made unify stop deducing T(2) == 1 for K during partial ordering for #1 and #2.
This minimal patch fixes this by making the relevant code in unify treat DEPENDENT_OPERATOR_TYPE like an empty type. Bootstrapped and regtested on x86_64-pc-linux-gnu, and preapproved for trunk by Jason off-list. Does this also look OK for the 12 branch? PR c++/105425 gcc/cp/ChangeLog: * pt.cc (unify) <case TEMPLATE_PARM_INDEX>: Treat DEPENDENT_OPERATOR_TYPE like an empty type. gcc/testsuite/ChangeLog: * g++.dg/template/partial-specialization13.C: New test. --- gcc/cp/pt.cc | 3 ++- .../g++.dg/template/partial-specialization13.C | 10 ++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/template/partial-specialization13.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 3cf1d7af8d2..cf24d482488 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -24276,7 +24276,8 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict, } } - if (!TREE_TYPE (arg)) + if (!TREE_TYPE (arg) + || TREE_CODE (TREE_TYPE (arg)) == DEPENDENT_OPERATOR_TYPE) /* Template-parameter dependent expression. Just accept it for now. It will later be processed in convert_template_argument. */ ; diff --git a/gcc/testsuite/g++.dg/template/partial-specialization13.C b/gcc/testsuite/g++.dg/template/partial-specialization13.C new file mode 100644 index 00000000000..e0a115cd06c --- /dev/null +++ b/gcc/testsuite/g++.dg/template/partial-specialization13.C @@ -0,0 +1,10 @@ +// PR c++/105425 +// { dg-do compile { target c++11 } } + +template<bool> struct when; +template<class, class> struct A; +template<class T, bool K> struct A<T, when<K>>; // #1 +template<class T> struct A<T, when<T(2) == 1>> {}; // #2 +A<int, when<true>> a1; // { dg-error "incomplete" } +A<int, when<false>> a2; +A<bool, when<true>> a3; -- 2.36.0.rc2.10.g1ac7422e39