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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/51385] Unnecessary instantiation converting to pointer to template class instance Date: Fri, 02 Dec 2011 10:36:00 -0000 [thread overview] Message-ID: <bug-51385-4-2bYXFmEWXn@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-51385-4@http.gcc.gnu.org/bugzilla/> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51385 --- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-12-02 10:36:14 UTC --- Here's a version which isn't a compile-time-hog but demonstrates the unnecessary instantiation with a static_assert (so needs -std=c++11) template <unsigned N> struct NTmpl; template <typename T, typename U, typename V = NTmpl<sizeof(T *)> > struct PtrConvs { enum { bad = 1 }; }; template <typename Target, typename Source> struct PtrConvs<Target, Source, NTmpl<sizeof (*(Target **)0 = (Source *)0)> >; template<typename T> struct test { static const bool value = true; }; template<> struct test<short> { static const bool value = false; }; template <typename T> struct FussyTemplate { static_assert( test<T>::value, "not short" ); }; struct B { }; typedef char chk[1]; typedef char chk[PtrConvs<FussyTemplate<short>, B>::bad]; EFG and Clang compile this happily, without instantiating FussyTemplate<short>
next prev parent reply other threads:[~2011-12-02 10:36 UTC|newest] Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-12-01 23:32 [Bug c++/51385] New: " hstong at ca dot ibm.com 2011-12-02 10:36 ` redi at gcc dot gnu.org [this message] 2011-12-02 10:43 ` [Bug c++/51385] " paolo.carlini at oracle dot com 2011-12-02 10:48 ` redi at gcc dot gnu.org 2014-09-29 8:55 ` paolo.carlini at oracle dot com 2014-09-29 9:07 ` paolo at gcc dot gnu.org 2014-09-29 9:08 ` paolo.carlini at oracle dot com
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