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author | Marek Polacek <polacek@redhat.com> | 2020-07-16 09:15:37 -0400 |
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committer | Marek Polacek <polacek@redhat.com> | 2020-08-03 17:43:05 -0400 |
commit | 50bee766bc9f4020cf1f814178155d16e80dccaa (patch) | |
tree | da6017acebc2d48197ef88ff2254c624160cb003 | |
parent | 90b43856fdff7d96d93d22970eca8a86c56e0ddc (diff) | |
download | gcc-50bee766bc9f4020cf1f814178155d16e80dccaa.zip gcc-50bee766bc9f4020cf1f814178155d16e80dccaa.tar.gz gcc-50bee766bc9f4020cf1f814178155d16e80dccaa.tar.bz2 |
c++: Variable template and template parameter pack [PR96218]
This is DR 2032 which says that the restrictions regarding template
parameter packs and default arguments apply to variable templates as
well, but we weren't detecting that.
gcc/cp/ChangeLog:
DR 2032
PR c++/96218
* pt.c (check_default_tmpl_args): Also consider variable
templates.
gcc/testsuite/ChangeLog:
DR 2032
PR c++/96218
* g++.dg/cpp1y/var-templ67.C: New test.
-rw-r--r-- | gcc/cp/pt.c | 5 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/cpp1y/var-templ67.C | 16 |
2 files changed, 19 insertions, 2 deletions
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 72bdf86..bd2af8b 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -5482,14 +5482,15 @@ check_default_tmpl_args (tree decl, tree parms, bool is_primary, /* Don't complain about an enclosing partial specialization. */ && parm_level == parms - && TREE_CODE (decl) == TYPE_DECL + && (TREE_CODE (decl) == TYPE_DECL || VAR_P (decl)) && i < ntparms - 1 && template_parameter_pack_p (TREE_VALUE (parm)) /* A fixed parameter pack will be partially instantiated into a fixed length list. */ && !fixed_parameter_pack_p (TREE_VALUE (parm))) { - /* A primary class template can only have one + /* A primary class template, primary variable template + (DR 2032), or alias template can only have one parameter pack, at the end of the template parameter list. */ diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ67.C b/gcc/testsuite/g++.dg/cpp1y/var-templ67.C new file mode 100644 index 0000000..f36af39 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp1y/var-templ67.C @@ -0,0 +1,16 @@ +// DR 2032 - Default template-arguments of variable templates +// PR c++/96218 +// { dg-do compile { target c++14 } } + +// [temp.param]/14: If a template-parameter of a class template, variable +// template, or alias template has a default template-argument, each subsequent +// template-parameter shall either have a default template-argument supplied or +// be a template parameter pack. +template<typename T = int, typename U> +T vt; // { dg-error "no default argument" } + +// [temp.param]/14: If a template-parameter of a primary class template, +// primary variable template, or alias template is a template parameter pack, +// it shall be the last template-parameter. +template<typename... Ts, typename U> // { dg-error "must be at the end" } +int vt2; |