sberg added a comment.
And, again for the record, with a build of LibreOffice with clang-cl (and
`-Xclang -std=c++2b`) on Windows, at least against the C++ standard library
from Visual Studio 2019 version 16.20.2, I ran into two issues in the standard
library itself, when using `std::getline` and `std::istream::operator>>`:
In file included from
C:/lo-clang/core/setup_native/source/win32/customactions/reg_dlls/reg_dlls.cxx:12:
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\string(66,12):
error: non-const lvalue reference to type 'basic_istream<...>' cannot bind to
a temporary of type 'basic_istream<...>'
return _Istr;
^~~~~
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\string(78,12):
note: in instantiation of function template specialization
'std::getline<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t>>'
requested here
return getline(_STD move(_Istr), _Str, _Delim);
^
C:/lo-clang/core/setup_native/source/win32/customactions/reg_dlls/reg_dlls.cxx(197,17):
note: in instantiation of function template specialization
'std::getline<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t>>'
requested here
while (std::getline(ss, sToken, L'|'))
^
1 error generated.
make[1]: *** [C:/lo-clang/core/solenv/gbuild/LinkTarget.mk:298:
C:/lo-clang/core/workdir/CxxObject/setup_native/source/win32/customactions/reg_dlls/reg_dlls.o]
Error 1
c:/Program Files (x86)/Microsoft Visual
Studio/2019/Community/VC/Tools/MSVC/14.29.30037/include/string
and
[build CXX] l10ntools/source/merge.cxx
In file included from C:/lo-clang/core/l10ntools/source/merge.cxx:21:
In file included from C:/lo-clang/core/include\sal/log.hxx:20:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\sstream:11:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\istream:11:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\ostream:11:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\ios:11:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\xlocnum:16:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\streambuf:11:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\xiosbase:12:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\system_error:14:
In file included from
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\stdexcept:12:
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\xstring(4971,12):
error: non-const lvalue reference to type 'basic_istream<...>' cannot bind to
a temporary of type 'basic_istream<...>'
return _Istr;
^~~~~
C:/PROGRA~2/MIB055~1/2019/COMMUN~1/VC/Tools/MSVC/1429~1.300/Include\xstring(4977,29):
note: in instantiation of function template specialization
'std::operator>><char, std::char_traits<char>, std::allocator<char>>' requested
here
return _STD move(_Istr) >> _Str;
^
C:/lo-clang/core/l10ntools/source/merge.cxx(125,18): note: in instantiation
of function template specialization 'std::operator>><char,
std::char_traits<char>, std::allocator<char>>' requested here
aInputStream >> sPoFile;
^
1 error generated.
make[1]: *** [C:/lo-clang/core/solenv/gbuild/LinkTarget.mk:301:
C:/lo-clang/core/workdir/CxxObject/l10ntools/source/merge.o] Error 1
In both cases, the reason is that library happens to implement the overload
taking `basic_istream&` by forwarding to the overload taking `basic_istream&&`
(and not the other way around, as libc++ and libstdc++ happen to do), and the
fix is to replace
return _Istr;
in the overloads taking `basic_istream&& _Istr` with
return static_cast<basic_istream<_Elem, _Traits>&>(_Istr);
(No idea if any MSVC standard library developers are around here, who might
want to be CC'ed on this.)
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D99005/new/
https://reviews.llvm.org/D99005
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