Skip to content

Implement char8_t compatibility remedies #470

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Casey Carter (CaseyCarter) merged 7 commits into from
Feb 1, 2020
Merged

Implement char8_t compatibility remedies #470

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
57b6f21
[ostream] Add deleted charX_t overloads to operator<<
miscco Jan 29, 2020
c38a7ac
Update stl/inc/ostream
miscco Jan 30, 2020
2386247
Mark it as controlled by CXX20
miscco Jan 30, 2020
469d6c3
Skip libcxx tests that expect the pre-1423 value of __cpp_lib_char8_t
CaseyCarter Jan 30, 2020
4f5c7ae
Add escape hatch _HAS_STREAM_INSERTIONS_REMOVED_BY_P1423 for non-`cha…
CaseyCarter Jan 30, 2020
47c9372
Change escape hatch name and default to !_HAS_CXX20
CaseyCarter Jan 31, 2020
53acdbf
Narrow stream insertion of unsigned short should work with /Zc:wchar_…
CaseyCarter Jan 31, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 38 additions & 4 deletions stl/inc/ostream
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -912,15 +912,49 @@ basic_ostream<char, _Traits>& operator<<(
}

#ifdef __cpp_char8_t // These deleted overloads are specified in P1423.
Comment thread
CaseyCarter marked this conversation as resolved.

@CaseyCarter Casey Carter (CaseyCarter) Jan 29, 2020

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Note to other reviewers: This means the char8_t overloads continue to be deleted even in sub-C++20 mode (e.g., if compiling with e.g. /std:c++17 /Zc:char8_t). I'm fine with this inconsistent behavior of char8_t vs. char16_t/char32_t, shout if you are not.

@DBJDBJ dbj (DBJDBJ) Mar 27, 2020

Copy link
Copy Markdown

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

That's fine, in any case only "he who likes pain" will use char8_t in C++20... Now, where is that Jens Gustedt pdf on modern C ... sorry talking to myself, have to go now... Good work Casey, thanks a lot, see you ...

// don't insert a UTF-8 NTBS
template <class _Traits>
basic_ostream<char, _Traits>& operator<<(
basic_ostream<char, _Traits>&, const char8_t*) = delete; // don't insert a UTF-8 NTBS
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char8_t*) = delete;
template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char8_t*) = delete;

// don't insert a UTF-8 code unit
Comment thread
miscco marked this conversation as resolved.
template <class _Traits>
basic_ostream<char, _Traits>& operator<<(
basic_ostream<char, _Traits>&, char8_t) = delete; // don't insert a UTF-8 code unit
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char8_t) = delete;
template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char8_t) = delete;
#endif // __cpp_char8_t

#if !_HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20
#ifdef _NATIVE_WCHAR_T_DEFINED
template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, wchar_t) = delete;

template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const wchar_t*) = delete;
#endif // _NATIVE_WCHAR_T_DEFINED

template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char16_t) = delete;
template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, char32_t) = delete;

template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char16_t) = delete;
template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, char32_t) = delete;

template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char16_t*) = delete;
template <class _Traits>
basic_ostream<char, _Traits>& operator<<(basic_ostream<char, _Traits>&, const char32_t*) = delete;

template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char16_t*) = delete;
template <class _Traits>
basic_ostream<wchar_t, _Traits>& operator<<(basic_ostream<wchar_t, _Traits>&, const char32_t*) = delete;
#endif // !_HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20

template <class _Ostr, class _Ty, class = void>
struct _Can_stream_out : false_type {};

Expand Down
9 changes: 8 additions & 1 deletion stl/inc/yvals_core.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -172,6 +172,7 @@
// P1227R2 Signed std::ssize(), Unsigned span::size()
// P1357R1 is_bounded_array, is_unbounded_array
// P1394R4 Range Constructor For span
// P1423R3 char8_t Backward Compatibility Remediation
// P1456R1 Move-Only Views
// P1612R1 Relocating endian To <bit>
// P1645R1 constexpr For <numeric> Algorithms
Expand Down Expand Up @@ -585,6 +586,12 @@
#endif // _M_FP_EXCEPT
#endif // _STD_VECTORIZE_WITH_FLOAT_CONTROL

// P1423R3 char8_t Backward Compatibility Remediation
// Controls whether we allow the stream insertions this proposal forbids
#ifndef _HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20
#define _HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20 (!_HAS_CXX20)
#endif // _HAS_STREAM_INSERTION_OPERATORS_DELETED_IN_CXX20

// P0174R2 Deprecating Vestigial Library Parts
// P0521R0 Deprecating shared_ptr::unique()
// Other C++17 deprecation warnings
Expand Down Expand Up @@ -1007,7 +1014,7 @@
#define __cpp_lib_bounded_array_traits 201902L

#ifdef __cpp_char8_t
#define __cpp_lib_char8_t 201811L
#define __cpp_lib_char8_t 201907L
Comment thread
StephanTLavavej marked this conversation as resolved.
#endif // __cpp_char8_t

#if defined(__cpp_concepts) && __cpp_concepts > 201507L
Expand Down
7 changes: 7 additions & 0 deletions tests/libcxx/skipped_tests.txt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -51,6 +51,13 @@ containers\unord\unord.set\insert_and_emplace_allocator_requirements.pass.cpp
# See https://reviews.llvm.org/D73138
containers\views\span.sub\subspan.pass.cpp

# libcxx doesn't yet implement P1423R3, so it expects an "old" value for __cpp_lib_char8_t
language.support\support.limits\support.limits.general\filesystem.version.pass.cpp
language.support\support.limits\support.limits.general\istream.version.pass.cpp
language.support\support.limits\support.limits.general\limits.version.pass.cpp
language.support\support.limits\support.limits.general\locale.version.pass.cpp
language.support\support.limits\support.limits.general\ostream.version.pass.cpp


# *** INTERACTIONS WITH CONTEST / C1XX THAT UPSTREAM LIKELY WON'T FIX ***
# Tracked by VSO-593630 "<filesystem> Enable libcxx filesystem tests"
Expand Down