This fixes an error when compiled with a copy of abseil-cpp that was compiled as C++14.
Description
When trying to compile this project in Fedora Linux against a system copy abseil-cpp (version 20230125.3) that was compiled as C++14 (instead of C++17), an error occurs:
../../unix/fcitx5/surrounding_text_util.cc: In function ‘bool fcitx::GetSurroundingText(InputContext*, SurroundingTextInfo*, AddonInstance*)’:
../../unix/fcitx5/surrounding_text_util.cc:216:68: error: no match for ‘operator=’ (operand types are ‘std::string’ {aka ‘std::__cxx11::basic_string<char>’} and ‘absl::lts_20230125::string_view’)
216 | Util::Utf8SubString(surrounding_text_view, 0, selection_start);
| ^
In file included from /usr/include/c++/13/string:54,
from /usr/include/Fcitx5/Core/fcitx/inputcontext.h:14,
from /builddir/build/BUILD/mozc/src/unix/fcitx5/surrounding_text_util.h:33,
from ../../unix/fcitx5/surrounding_text_util.cc:30:
/usr/include/c++/13/bits/basic_string.h:935:8: note: candidate: ‘template<class _Tp> std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::_If_sv<_Tp, std::__cxx11::basic_string<_CharT, _Traits, _Alloc>&> std::__cxx11::basic_string<_CharT,
_Traits, _Alloc>::operator=(const _Tp&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’
935 | operator=(const _Tp& __svt)
| ^~~~~~~~
I can’t easily explain why this is working when abseil-cpp is compiled as C++17, but it’s clear that the problem I’m encountering is in the implicit conversion from the absl::string_view returned by Util::Utf8SubString to the std::string needed for the assignment to a SurroundingTextInfo member. It’s my understanding that this isn’t supposed to be implicit, because it creates a copy.
Anyway, using the std::string constructor to create an copy solves the problem, and we can expect the copy from a temporary string to the struct member should be elided.
Issue IDs
N/A
Steps to test new behaviors (if any)
N/A: behavior should not change, except that a compiler error will not occur in some situations
This fixes an error when compiled with a copy of
abseil-cppthat was compiled as C++14.Description
When trying to compile this project in Fedora Linux against a system copy
abseil-cpp(version 20230125.3) that was compiled as C++14 (instead of C++17), an error occurs:I can’t easily explain why this is working when
abseil-cppis compiled as C++17, but it’s clear that the problem I’m encountering is in the implicit conversion from theabsl::string_viewreturned byUtil::Utf8SubStringto thestd::stringneeded for the assignment to aSurroundingTextInfomember. It’s my understanding that this isn’t supposed to be implicit, because it creates a copy.Anyway, using the
std::stringconstructor to create an copy solves the problem, and we can expect the copy from a temporary string to the struct member should be elided.Issue IDs
N/A
Steps to test new behaviors (if any)
N/A: behavior should not change, except that a compiler error will not occur in some situations
Additional context
N/A