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| author | Patrick Palka <ppalka@redhat.com> | 2025-09-12 14:21:25 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2025-09-12 14:21:25 -0400 |
| commit | 8e3230f4fed0d41e790d68c2534c057911bab35c (patch) | |
| tree | 9334eddd26d076565493b65cc7d72c707b7c61ce | |
| parent | d0c08415310d1daecb28f8fbfeef3d7f18b21d56 (diff) | |
| download | gcc-8e3230f4fed0d41e790d68c2534c057911bab35c.zip gcc-8e3230f4fed0d41e790d68c2534c057911bab35c.tar.gz gcc-8e3230f4fed0d41e790d68c2534c057911bab35c.tar.bz2 | |
c++: pack indexing is a non-deduced context [PR121795]
We weren't explicitly treating a pack index specifier as a non-deduced
context (as per [temp.deduct.type]/5), leading to an ICE for the first
testcase below.
PR c++/121795
gcc/cp/ChangeLog:
* pt.cc (unify) <case PACK_INDEX_TYPE>: New non-deduced context
case.
gcc/testsuite/ChangeLog:
* g++.dg/cpp26/pack-indexing17.C: New test.
* g++.dg/cpp26/pack-indexing17a.C: New test.
Reviewed-by: Marek Polacek <polacek@redhat.com>
Reviewed-by: Jason Merrill <jason@redhat.com>
| -rw-r--r-- | gcc/cp/pt.cc | 4 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp26/pack-indexing17.C | 11 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp26/pack-indexing17a.C | 12 |
3 files changed, 25 insertions, 2 deletions
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 7f0d16f..b7cb807 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -26301,8 +26301,8 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict, case TYPEOF_TYPE: case DECLTYPE_TYPE: case TRAIT_TYPE: - /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE, - or TRAIT_TYPE nodes. */ + case PACK_INDEX_TYPE: + /* These are non-deduced contexts. */ return unify_success (explain_p); case ERROR_MARK: diff --git a/gcc/testsuite/g++.dg/cpp26/pack-indexing17.C b/gcc/testsuite/g++.dg/cpp26/pack-indexing17.C new file mode 100644 index 0000000..8450ed6 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp26/pack-indexing17.C @@ -0,0 +1,11 @@ +// PR c++/121795 +// { dg-do compile { target c++26 } } + +template<class T, class... Ts> +struct A; + +template<class... Ts> +struct A<Ts...[sizeof...(Ts)-1], Ts...> { }; + +A<int, int> x; +A<char, int> y; // { dg-error "incomplete" } diff --git a/gcc/testsuite/g++.dg/cpp26/pack-indexing17a.C b/gcc/testsuite/g++.dg/cpp26/pack-indexing17a.C new file mode 100644 index 0000000..445f0d9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp26/pack-indexing17a.C @@ -0,0 +1,12 @@ +// PR c++/121795 +// A version of pack-indexing17.C using a nontype pack. +// { dg-do compile { target c++26 } } + +template<int N, int... Ns> +struct A; + +template<int... Ns> +struct A<Ns...[sizeof...(Ns)-1], Ns...> { }; + +A<0, 0> x; +A<0, 1> y; // { dg-error "incomplete" } |