https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99000
Bug ID: 99000
Summary: [modules] declaration std::__copy_move_a2 conflicts
with import
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: boris at kolpackov dot net
Target Milestone: ---
The following header unit import causes the "declaration conflicts with import"
error:
cat <<EOF >hello.hxx
#pragma once
#include <string_view>
namespace hello
{
void
say_hello (const std::string_view& name);
}
EOF
cat <<EOF >hello.cxx
import "hello.hxx";
#include <iostream>
namespace hello
{
void
say_hello (const std::string_view& n)
{
std::cout << "Hello, " << n << '!' << std::endl;
}
}
EOF
g++ -std=c++2a -fmodules-ts -fmodule-header -x c++-header hello.hxx
g++ -std=c++2a -fmodules-ts x c++ -c hello.cxx
In file included from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/bits/locale_facets.h:48,
from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/bits/basic_ios.h:37,
from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/ios:44,
from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/ostream:38,
from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/iostream:39,
from hello.cxx:3:
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/bits/streambuf_iterator.h:367:72:
error: declaration ‘template<bool _IsMove, class _CharT> typename
__gnu_cxx::__enable_if<std::__is_char<_CharT>::__value, _CharT*>::__type
std::__copy_move_a2(std::istreambuf_iterator<_CharT, std::char_traits<_CharT>
>, std::istreambuf_iterator<_CharT, std::char_traits<_CharT> >, _CharT*)’
conflicts with import
367 | istreambuf_iterator<_CharT> __last, _CharT*
__result)
|
^
In file included from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/bits/char_traits.h:39,
from
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/string_view:41,
from hello.hxx:3,
of module ./hello.hxx, imported at hello.cxx:1:
/home/boris/work/build2/tests/modules/gcc2/gcc-install/include/c++/11.0.0/bits/stl_algobase.h:471:5:
note: import declared ‘template<bool _IsMove, class _CharT> typename
__gnu_cxx::__enable_if<std::__is_char<_CharT>::__value, _CharT*>::__type
std::__copy_move_a2(std::istreambuf_iterator<_CharT, std::char_traits<_CharT>
>, std::istreambuf_iterator<_CharT, std::char_traits<_CharT> >, _CharT*)’ here
471 | __copy_move_a2(istreambuf_iterator<_CharT, char_traits<_CharT> >,
| ^~~~~~~~~~~~~~
Interestingly, if we change the #include and import order in hello.cxx, then
the error goes away.
