ср, 12 мая 2021 г. в 17:44, Jonathan Wakely <jwak...@redhat.com>: > > On 12/05/21 12:58 +0300, Antony Polukhin wrote: > >ср, 12 мая 2021 г. в 12:18, Jonathan Wakely <jwak...@redhat.com>: > ><...> > >> Or just leave it undefined, as libc++ seems to do according to your > >> comment in PR 89728: > >> > >> error: implicit instantiation of undefined template > >> 'std::__1::ctype<std::__1::basic_string<char> >' > >> > >> Was your aim to have a static_assert that gives a more descriptive > >> error? We could leave it undefined in C++98 and have the static assert > >> for C++11 and up. > > > >Leaving it undefined would be the best. It would allow SFINAE on ctype > >and a compile time error is informative enough. > > > >However, there may be users who instantiate ctype<ThierChar> in a > >shared library without ctype<ThierChar> template specializations in > >the main executable. Making the default ctype undefined would break > >their compilation: > > > >#include <locale> > >// no ctype<ThierChar> specialization > >c = std::tolower(ThierChar{42}, locale_from_shared_library()); // OK > >right now in libstdc++, fails on libc++ > > What I meant was leaving the partial specialization undefined, not the > primary template, i.e. > > --- a/libstdc++-v3/include/bits/locale_facets.h > +++ b/libstdc++-v3/include/bits/locale_facets.h > @@ -1476,6 +1476,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > }; > #endif //_GLIBCXX_USE_WCHAR_T > > + template<typename _CharT, typename _Traits, typename _Alloc> > + class ctype<basic_string<_CharT, _Traits, _Alloc> >; > + > /// class ctype_byname [22.2.1.2]. > template<typename _CharT> > class ctype_byname : public ctype<_CharT> > > This makes your test fail with errors like this: > > In file included from /home/jwakely/gcc/12/include/c++/12.0.0/locale:40, > from loc.C:1: > /home/jwakely/gcc/12/include/c++/12.0.0/bits/locale_facets.h: In > instantiation of 'bool std::isspace(_CharT, const std::locale&) [with _CharT > = std::__cxx11::basic_string<char>]': > loc.C:16:15: required from here > /home/jwakely/gcc/12/include/c++/12.0.0/bits/locale_facets.h:2600:47: error: > invalid use of incomplete type 'const class > std::ctype<std::__cxx11::basic_string<char> >' > 2600 | { return use_facet<ctype<_CharT> >(__loc).is(ctype_base::space, > __c); } > | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ > > But it shouldn't affect the uses of ctype<TheirChar>. > > What do you think?
Good idea. That way the compiler message points directly to the misused function. Patch is in attachment -- Best regards, Antony Polukhin
diff --git a/libstdc++-v3/include/bits/locale_facets.h b/libstdc++-v3/include/bits/locale_facets.h index 03724cf..5ca431e 100644 --- a/libstdc++-v3/include/bits/locale_facets.h +++ b/libstdc++-v3/include/bits/locale_facets.h @@ -671,6 +671,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _CharT> locale::id ctype<_CharT>::id; + // Incomplete to provide a compile time diagnostics for common misuse + // of [locale.convenience] functions with basic_string as a character type. + template<typename _CharT, typename _Traits, typename _Alloc> + class ctype<basic_string<_CharT, _Traits, _Alloc> >; + /** * @brief The ctype<char> specialization. * @ingroup locales diff --git a/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc b/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc new file mode 100644 index 0000000..ccab3a2 --- /dev/null +++ b/libstdc++-v3/testsuite/22_locale/ctype/is/string/89728_neg.cc @@ -0,0 +1,73 @@ +// { dg-do compile } + +// Copyright (C) 2021 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-error "complete" "" { target *-*-* } 0 } + +#include <locale> + +template <class Char, int I> +struct trait: std::char_traits<Char> {}; + +template <class Char, int I> +std::basic_string<Char, trait<Char, I> > make_str() +{ + return std::basic_string<Char, trait<Char, I> >(); +} + +void test01() +{ + const std::locale& loc = std::locale::classic(); + + std::isspace(std::string{}, loc); // { dg-error "required from here" } + std::isprint(make_str<char, 0>(), loc); // { dg-error "required from here" } + std::iscntrl(make_str<char, 1>(), loc); // { dg-error "required from here" } + std::isupper(make_str<char, 2>(), loc); // { dg-error "required from here" } + std::islower(make_str<char, 3>(), loc); // { dg-error "required from here" } + std::isalpha(make_str<char, 4>(), loc); // { dg-error "required from here" } + std::isdigit(make_str<char, 5>(), loc); // { dg-error "required from here" } + std::ispunct(make_str<char, 6>(), loc); // { dg-error "required from here" } + std::isxdigit(make_str<char, 7>(), loc); // { dg-error "required from here" } + std::isalnum(make_str<char, 8>(), loc); // { dg-error "required from here" } + std::isgraph(make_str<char, 9>(), loc); // { dg-error "required from here" } + std::isblank(make_str<char, 10>(), loc); // { dg-error "required from here" } + std::toupper(make_str<char, 11>(), loc); // { dg-error "required from here" } + std::tolower(make_str<char, 12>(), loc); // { dg-error "required from here" } +} + +#ifdef _GLIBCXX_USE_WCHAR_T +void test02() +{ + const std::locale& loc = std::locale::classic(); + + std::isspace(std::wstring{}, loc); // { dg-error "required from here" } + std::isprint(make_str<wchar_t, 0>(), loc); // { dg-error "required from here" } + std::iscntrl(make_str<wchar_t, 1>(), loc); // { dg-error "required from here" } + std::isupper(make_str<wchar_t, 2>(), loc); // { dg-error "required from here" } + std::islower(make_str<wchar_t, 3>(), loc); // { dg-error "required from here" } + std::isalpha(make_str<wchar_t, 4>(), loc); // { dg-error "required from here" } + std::isdigit(make_str<wchar_t, 5>(), loc); // { dg-error "required from here" } + std::ispunct(make_str<wchar_t, 6>(), loc); // { dg-error "required from here" } + std::isxdigit(make_str<wchar_t, 7>(), loc); // { dg-error "required from here" } + std::isalnum(make_str<wchar_t, 8>(), loc); // { dg-error "required from here" } + std::isgraph(make_str<wchar_t, 9>(), loc); // { dg-error "required from here" } + std::isblank(make_str<wchar_t, 10>(), loc); // { dg-error "required from here" } + std::toupper(make_str<wchar_t, 11>(), loc); // { dg-error "required from here" } + std::tolower(make_str<wchar_t, 12>(), loc); // { dg-error "required from here" } +} +#endif