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| author | Patrick Palka <ppalka@redhat.com> | 2021-04-12 23:22:03 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2021-04-12 23:22:03 -0400 |
| commit | c755e1b3eadaf1c7e751a2c7ce1d418c6db8463a (patch) | |
| tree | 6c05c93bba896feb39bfe252e6761351c83877bf /gcc | |
| parent | 59d9aa6d2efe7c52b6a986eb3e1977c1fb3c5753 (diff) | |
| download | gcc-c755e1b3eadaf1c7e751a2c7ce1d418c6db8463a.zip gcc-c755e1b3eadaf1c7e751a2c7ce1d418c6db8463a.tar.gz gcc-c755e1b3eadaf1c7e751a2c7ce1d418c6db8463a.tar.bz2 | |
c++: variadic class template placeholder deduction [PR97134]
do_class_deduction handles specially the case where we're deducing one
placeholder from another equivalent one, but here the initializer passed
to do_class_deduction is wrapped in an EXPR_PACK_EXPANSION (we're being
called from unify during get_partial_spec_bindings). This patch makes
do_class_deduction look through EXPR_PACK_EXPANSIONs so that we detect
this case as well.
gcc/cp/ChangeLog:
PR c++/97134
* pt.c (do_class_deduction): Look through EXPR_PACK_EXPANSION
when checking if the initializer is an equivalent class
placeholder template parameter.
gcc/testsuite/ChangeLog:
PR c++/97134
* g++.dg/cpp2a/nontype-class43.C: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/pt.c | 6 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/nontype-class43.C | 11 |
2 files changed, 16 insertions, 1 deletions
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index efcbc59..6b63edd 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -29286,7 +29286,11 @@ do_class_deduction (tree ptype, tree tmpl, tree init, return ptype; /* Initializing one placeholder from another. */ - if (init && TREE_CODE (init) == TEMPLATE_PARM_INDEX + if (init + && (TREE_CODE (init) == TEMPLATE_PARM_INDEX + || (TREE_CODE (init) == EXPR_PACK_EXPANSION + && (TREE_CODE (PACK_EXPANSION_PATTERN (init)) + == TEMPLATE_PARM_INDEX))) && is_auto (TREE_TYPE (init)) && CLASS_PLACEHOLDER_TEMPLATE (TREE_TYPE (init)) == tmpl) return cp_build_qualified_type (TREE_TYPE (init), cp_type_quals (ptype)); diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class43.C b/gcc/testsuite/g++.dg/cpp2a/nontype-class43.C new file mode 100644 index 0000000..f51684f --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class43.C @@ -0,0 +1,11 @@ +// PR c++/97134 +// { dg-do compile { target c++20 } } + +template<typename T> +struct templ {}; + +template<templ... Vs> +struct wrapper {}; + +template<templ... Vs> requires true +struct wrapper<Vs...> {}; |