[libcxx-commits] [libcxx] WIP - [libc++][spanstream] P0448R4: A `strstream` replacement using `span<charT>` as buffer (PR #83541)
via libcxx-commits
libcxx-commits at lists.llvm.org
Fri Mar 1 00:37:02 PST 2024
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libcxx
Author: Hristo Hristov (H-G-Hristov)
<details>
<summary>Changes</summary>
Implements: P0448R https://wg21.link/P0448R4
- https://eel.is/c++draft/span.streams
- https://eel.is/c++draft/spanbuf
- https://eel.is/c++draft/ispanstream
- https://eel.is/c++draft/ospanstream
- https://eel.is/c++draft/spanstream
---
Patch is 84.49 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/83541.diff
38 Files Affected:
- (modified) libcxx/docs/FeatureTestMacroTable.rst (+1-1)
- (modified) libcxx/docs/ReleaseNotes/19.rst (+1)
- (modified) libcxx/docs/Status/Cxx23Papers.csv (+1-1)
- (modified) libcxx/include/CMakeLists.txt (+2)
- (added) libcxx/include/__fwd/spanstream.h (+48)
- (modified) libcxx/include/__std_clang_module (+3)
- (modified) libcxx/include/iosfwd (+20)
- (modified) libcxx/include/libcxx.imp (+1)
- (modified) libcxx/include/module.modulemap.in (+12-7)
- (added) libcxx/include/spanstream (+435)
- (modified) libcxx/include/version (+1-1)
- (modified) libcxx/modules/std.compat.cppm.in (-3)
- (modified) libcxx/modules/std.cppm.in (+3-3)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/ispanstream.cons/move.pass.cpp (+81)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/ispanstream.cons/ros.pass.cpp (+60)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/ispanstream.cons/span.mode.pass.cpp (+136)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/ispanstream.general/lit.local.cfg (+3)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/ispanstream.general/nothing_to_do.pass.cpp (+15)
- (added) libcxx/test/std/input.output/span.streams/ispanstream/types.compile.pass.cpp (+79)
- (added) libcxx/test/std/input.output/span.streams/macros.h (+18)
- (added) libcxx/test/std/input.output/span.streams/ospanstream/ospanstream.general/lit.local.cfg (+3)
- (added) libcxx/test/std/input.output/span.streams/ospanstream/ospanstream.general/nothing_to_do.pass.cpp (+15)
- (added) libcxx/test/std/input.output/span.streams/ospanstream/types.compile.pass.cpp (+79)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.cons/default.pass.cpp (+46)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.cons/mode.pass.cpp (+101)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.cons/move.pass.cpp (+242)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.cons/span.mode.pass.cpp (+187)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.general/lit.local.cfg (+3)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/spanbuf.general/nothing_to_do.pass.cpp (+15)
- (added) libcxx/test/std/input.output/span.streams/spanbuf/types.compile.pass.cpp (+79)
- (added) libcxx/test/std/input.output/span.streams/spanstream/spanstream.general/lit.local.cfg (+3)
- (added) libcxx/test/std/input.output/span.streams/spanstream/spanstream.general/nothing_to_do.pass.cpp (+15)
- (added) libcxx/test/std/input.output/span.streams/spanstream/types.compile.pass.cpp (+79)
- (added) libcxx/test/std/input.output/span.streams/types.h (+73)
- (added) libcxx/test/std/language.support/support.limits/support.limits.general/spanstream.version.compile.pass.cpp (+68)
- (modified) libcxx/test/std/language.support/support.limits/support.limits.general/version.version.compile.pass.cpp (+10-22)
- (modified) libcxx/utils/generate_feature_test_macro_components.py (-1)
- (modified) libcxx/utils/libcxx/header_information.py (+2-1)
``````````diff
diff --git a/libcxx/docs/FeatureTestMacroTable.rst b/libcxx/docs/FeatureTestMacroTable.rst
index 468226c0c2dddf..1c39df01b3f0ee 100644
--- a/libcxx/docs/FeatureTestMacroTable.rst
+++ b/libcxx/docs/FeatureTestMacroTable.rst
@@ -370,7 +370,7 @@ Status
--------------------------------------------------- -----------------
``__cpp_lib_reference_from_temporary`` *unimplemented*
--------------------------------------------------- -----------------
- ``__cpp_lib_spanstream`` *unimplemented*
+ ``__cpp_lib_spanstream`` ``202106L``
--------------------------------------------------- -----------------
``__cpp_lib_stacktrace`` *unimplemented*
--------------------------------------------------- -----------------
diff --git a/libcxx/docs/ReleaseNotes/19.rst b/libcxx/docs/ReleaseNotes/19.rst
index 78c6bb87a5a402..536960b4681298 100644
--- a/libcxx/docs/ReleaseNotes/19.rst
+++ b/libcxx/docs/ReleaseNotes/19.rst
@@ -41,6 +41,7 @@ Implemented Papers
- P2637R3 - Member ``visit``
- P2652R2 - Disallow User Specialization of ``allocator_traits``
- P2819R2 - Add ``tuple`` protocol to ``complex``
+- P0448R4 - A ``strstream`` replacement using ``span<charT>`` as buffer
Improvements and New Features
diff --git a/libcxx/docs/Status/Cxx23Papers.csv b/libcxx/docs/Status/Cxx23Papers.csv
index eb415ed8c031fa..084c101ece9392 100644
--- a/libcxx/docs/Status/Cxx23Papers.csv
+++ b/libcxx/docs/Status/Cxx23Papers.csv
@@ -12,7 +12,7 @@
"`P2259R1 <https://wg21.link/P2259R1>`__","LWG","Repairing input range adaptors and counted_iterator","February 2021","","","|ranges|"
"","","","","","",""
"`P0401R6 <https://wg21.link/P0401R6>`__","LWG","Providing size feedback in the Allocator interface","June 2021","|Complete|","15.0"
-"`P0448R4 <https://wg21.link/P0448R4>`__","LWG","A strstream replacement using span<charT> as buffer","June 2021","",""
+"`P0448R4 <https://wg21.link/P0448R4>`__","LWG","A ``strstream`` replacement using ``span<charT>`` as buffer","June 2021","|Partial|","19.0"
"`P1132R8 <https://wg21.link/P1132R8>`__","LWG","out_ptr - a scalable output pointer abstraction","June 2021","",""
"`P1328R1 <https://wg21.link/P1328R1>`__","LWG","Making std::type_info::operator== constexpr","June 2021","|Complete|","17.0"
"`P1425R4 <https://wg21.link/P1425R4>`__","LWG","Iterators pair constructors for stack and queue","June 2021","|Complete|","14.0","|ranges|"
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index cafd8c6e00d968..024d4e0a6f523d 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -439,6 +439,7 @@ set(files
__fwd/ostream.h
__fwd/pair.h
__fwd/span.h
+ __fwd/spanstream.h
__fwd/sstream.h
__fwd/streambuf.h
__fwd/string.h
@@ -986,6 +987,7 @@ set(files
shared_mutex
source_location
span
+ spanstream
sstream
stack
stdatomic.h
diff --git a/libcxx/include/__fwd/spanstream.h b/libcxx/include/__fwd/spanstream.h
new file mode 100644
index 00000000000000..f5ff2ad2c9cfc6
--- /dev/null
+++ b/libcxx/include/__fwd/spanstream.h
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___FWD_SPANSTREAM_H
+#define _LIBCPP___FWD_SPANSTREAM_H
+
+#include <__config>
+#include <__fwd/string.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER >= 23
+
+template <class _CharT, class _Traits = char_traits<_CharT>>
+class _LIBCPP_TEMPLATE_VIS basic_spanbuf;
+template <class _CharT, class _Traits = char_traits<_CharT>>
+class _LIBCPP_TEMPLATE_VIS basic_ispanstream;
+template <class _CharT, class _Traits = char_traits<_CharT>>
+class _LIBCPP_TEMPLATE_VIS basic_ospanstream;
+template <class _CharT, class _Traits = char_traits<_CharT>>
+class _LIBCPP_TEMPLATE_VIS basic_spanstream;
+
+using spanbuf = basic_spanbuf<char>;
+using ispanstream = basic_ispanstream<char>;
+using ospanstream = basic_ospanstream<char>;
+using spanstream = basic_spanstream<char>;
+
+# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+using wspanbuf = basic_spanbuf<wchar_t>;
+using wispanstream = basic_ispanstream<wchar_t>;
+using wospanstream = basic_ospanstream<wchar_t>;
+using wspanstream = basic_spanstream<wchar_t>;
+# endif
+
+#endif // _LIBCPP_STD_VER >= 23
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___FWD_SPANSTREAM_H
diff --git a/libcxx/include/__std_clang_module b/libcxx/include/__std_clang_module
index 18d6ce6b46c1f6..f7cefc697c316f 100644
--- a/libcxx/include/__std_clang_module
+++ b/libcxx/include/__std_clang_module
@@ -163,6 +163,9 @@
#include <source_location>
#include <span>
#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+# include <spanstream>
+#endif
+#if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
# include <sstream>
#endif
#include <stack>
diff --git a/libcxx/include/iosfwd b/libcxx/include/iosfwd
index e28998d004156d..c760284f0dee88 100644
--- a/libcxx/include/iosfwd
+++ b/libcxx/include/iosfwd
@@ -42,6 +42,15 @@ template <class charT, class traits = char_traits<charT>, class Allocator = allo
template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
class basic_stringstream;
+ template<class charT, class traits = char_traits<charT>>
+ class basic_spanbuf; // Since C++23
+ template<class charT, class traits = char_traits<charT>>
+ class basic_ispanstream; // Since C++23
+ template<class charT, class traits = char_traits<charT>>
+ class basic_ospanstream; // Since C++23
+ template<class charT, class traits = char_traits<charT>>
+ class basic_spanstream; // Since C++23
+
template <class charT, class traits = char_traits<charT> > class basic_filebuf;
template <class charT, class traits = char_traits<charT> > class basic_ifstream;
template <class charT, class traits = char_traits<charT> > class basic_ofstream;
@@ -63,6 +72,11 @@ typedef basic_istringstream<char> istringstream;
typedef basic_ostringstream<char> ostringstream;
typedef basic_stringstream<char> stringstream;
+using spanbuf = basic_spanbuf<char>; // Since C++23
+using ispanstream = basic_ispanstream<char>; // Since C++23
+using ospanstream = basic_ospanstream<char>; // Since C++23
+using spanstream = basic_spanstream<char>; // Since C++23
+
typedef basic_filebuf<char> filebuf;
typedef basic_ifstream<char> ifstream;
typedef basic_ofstream<char> ofstream;
@@ -78,6 +92,11 @@ typedef basic_istringstream<wchar_t> wistringstream;
typedef basic_ostringstream<wchar_t> wostringstream;
typedef basic_stringstream<wchar_t> wstringstream;
+using wspanbuf = basic_spanbuf<wchar_t>; // Since C++23
+using wispanstream = basic_ispanstream<wchar_t>; // Since C++23
+using wospanstream = basic_ospanstream<wchar_t>; // Since C++23
+using wspanstream = basic_spanstream<wchar_t>; // Since C++23
+
typedef basic_filebuf<wchar_t> wfilebuf;
typedef basic_ifstream<wchar_t> wifstream;
typedef basic_ofstream<wchar_t> wofstream;
@@ -112,6 +131,7 @@ using wosyncstream = basic_osyncstream<wchar_t>; // C++20
#include <__fwd/ios.h>
#include <__fwd/istream.h>
#include <__fwd/ostream.h>
+#include <__fwd/spanstream.h>
#include <__fwd/sstream.h>
#include <__fwd/streambuf.h>
#include <__fwd/string.h>
diff --git a/libcxx/include/libcxx.imp b/libcxx/include/libcxx.imp
index 22fbea99b848bb..c25f0bbd215031 100644
--- a/libcxx/include/libcxx.imp
+++ b/libcxx/include/libcxx.imp
@@ -434,6 +434,7 @@
{ include: [ "<__fwd/ostream.h>", "private", "<ostream>", "public" ] },
{ include: [ "<__fwd/pair.h>", "private", "<utility>", "public" ] },
{ include: [ "<__fwd/span.h>", "private", "<span>", "public" ] },
+ { include: [ "<__fwd/spanstream.h>", "private", "<spanstream>", "public" ] },
{ include: [ "<__fwd/sstream.h>", "private", "<sstream>", "public" ] },
{ include: [ "<__fwd/streambuf.h>", "private", "<streambuf>", "public" ] },
{ include: [ "<__fwd/string.h>", "private", "<string>", "public" ] },
diff --git a/libcxx/include/module.modulemap.in b/libcxx/include/module.modulemap.in
index 219906aa9a5668..00d877960a4cc4 100644
--- a/libcxx/include/module.modulemap.in
+++ b/libcxx/include/module.modulemap.in
@@ -233,6 +233,10 @@ module std_span [system] {
export std_version
export std_private_span_span_fwd
}
+module std_spanstream [system] {
+ header "spanstream"
+ export *
+}
module std_sstream [system] {
header "sstream"
export *
@@ -1388,14 +1392,15 @@ module std_private_functional_unary_function [system] { header "__fu
module std_private_functional_unary_negate [system] { header "__functional/unary_negate.h" }
module std_private_functional_weak_result_type [system] { header "__functional/weak_result_type.h" }
-module std_private_ios_fpos [system] { header "__ios/fpos.h" }
+module std_private_ios_fpos [system] { header "__ios/fpos.h" }
-module std_private_iosfwd_fstream_fwd [system] { header "__fwd/fstream.h" }
-module std_private_iosfwd_ios_fwd [system] { header "__fwd/ios.h" }
-module std_private_iosfwd_istream_fwd [system] { header "__fwd/istream.h" }
-module std_private_iosfwd_ostream_fwd [system] { header "__fwd/ostream.h" }
-module std_private_iosfwd_sstream_fwd [system] { header "__fwd/sstream.h" }
-module std_private_iosfwd_streambuf_fwd [system] { header "__fwd/streambuf.h" }
+module std_private_iosfwd_fstream_fwd [system] { header "__fwd/fstream.h" }
+module std_private_iosfwd_ios_fwd [system] { header "__fwd/ios.h" }
+module std_private_iosfwd_istream_fwd [system] { header "__fwd/istream.h" }
+module std_private_iosfwd_ostream_fwd [system] { header "__fwd/ostream.h" }
+module std_private_iosfwd_spanstream_fwd [system] { header "__fwd/spanstream.h" }
+module std_private_iosfwd_sstream_fwd [system] { header "__fwd/sstream.h" }
+module std_private_iosfwd_streambuf_fwd [system] { header "__fwd/streambuf.h" }
module std_private_iterator_access [system] { header "__iterator/access.h" }
module std_private_iterator_advance [system] { header "__iterator/advance.h" }
diff --git a/libcxx/include/spanstream b/libcxx/include/spanstream
new file mode 100644
index 00000000000000..16bbf04d81c559
--- /dev/null
+++ b/libcxx/include/spanstream
@@ -0,0 +1,435 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_SPANSTREAM
+#define _LIBCPP_SPANSTREAM
+
+// clang-format off
+
+/*
+ Span-based streams [span.streams]
+
+ template<class charT, class traits = char_traits<charT>>
+ class basic_spanbuf;
+
+ template<class charT, class traits>
+ void swap(basic_spanbuf<charT, traits>& x, basic_spanbuf<charT, traits>& y);
+
+ using spanbuf = basic_spanbuf<char>;
+ using wspanbuf = basic_spanbuf<wchar_t>;
+
+ template<class charT, class traits = char_traits<charT>>
+ class basic_ispanstream;
+
+ template<class charT, class traits>
+ void swap(basic_ispanstream<charT, traits>& x, basic_ispanstream<charT, traits>& y);
+
+ using ispanstream = basic_ispanstream<char>;
+ using wispanstream = basic_ispanstream<wchar_t>;
+
+ template<class charT, class traits = char_traits<charT>>
+ class basic_ospanstream;
+
+ template<class charT, class traits>
+ void swap(basic_ospanstream<charT, traits>& x, basic_ospanstream<charT, traits>& y);
+
+ using ospanstream = basic_ospanstream<char>;
+ using wospanstream = basic_ospanstream<wchar_t>;
+
+ template<class charT, class traits = char_traits<charT>>
+ class basic_spanstream;
+
+ template<class charT, class traits>
+ void swap(basic_spanstream<charT, traits>& x, basic_spanstream<charT, traits>& y);
+
+ using spanstream = basic_spanstream<char>;
+ using wspanstream = basic_spanstream<wchar_t>;
+*/
+
+// clang-format on
+
+#include <__assert> // all public C++ headers provide the assertion handler
+#include <__availability>
+#include <__config>
+#include <__fwd/spanstream.h>
+#include <__memory/addressof.h>
+#include <__ranges/concepts.h>
+#include <__utility/cmp.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+#include <__utility/swap.h>
+#include <iostream>
+#include <span>
+#include <streambuf>
+#include <version>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+#if _LIBCPP_STD_VER >= 23
+
+// Class template basic_spanbuf [spanbuf]
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_spanbuf : public basic_streambuf<_CharT, _Traits> {
+public:
+ using char_type = _CharT;
+ using int_type = typename _Traits::int_type;
+ using pos_type = typename _Traits::pos_type;
+ using off_type = typename _Traits::off_type;
+ using traits_type = _Traits;
+
+ // [spanbuf.cons], constructors
+
+ _LIBCPP_HIDE_FROM_ABI basic_spanbuf() : basic_spanbuf(ios_base::in | ios_base::out) {}
+
+ _LIBCPP_HIDE_FROM_ABI explicit basic_spanbuf(ios_base::openmode __which)
+ : basic_spanbuf(std::span<_CharT>(), __which) {}
+
+ _LIBCPP_HIDE_FROM_ABI explicit basic_spanbuf(std::span<_CharT> __s,
+ ios_base::openmode __which = ios_base::in | ios_base::out)
+ : basic_streambuf<_CharT, _Traits>{}, __mode_{__which}, __buf_{__s} {
+ this->span(__s);
+ }
+
+ basic_spanbuf(const basic_spanbuf&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI basic_spanbuf(basic_spanbuf&& __rhs)
+ : basic_streambuf<_CharT, _Traits>{std::move(__rhs)},
+ __mode_{std::move(__rhs.__mode_)},
+ __buf_{std::move(__rhs.__buf_)} {}
+
+ // [spanbuf.assign], assignment and swap
+
+ basic_spanbuf& operator=(const basic_spanbuf&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI basic_spanbuf& operator=(basic_spanbuf&& __rhs) {
+ basic_spanbuf __tmp{std::move(__rhs)};
+ this->swap(__tmp);
+ return *this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void swap(basic_spanbuf& __rhs) {
+ basic_streambuf<_CharT, _Traits>::swap(__rhs);
+ std::swap(__mode_, __rhs.__mode_);
+ std::swap(__buf_, __rhs.__buf_);
+ }
+
+ // [spanbuf.members], member functions
+
+ _LIBCPP_HIDE_FROM_ABI std::span<_CharT> span() const noexcept {
+ if (__mode_ & ios_base::out) {
+ return std::span<_CharT>(this->pbase(), this->pptr());
+ }
+ return __buf_;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI void span(std::span<_CharT> __s) noexcept {
+ __buf_ = __s;
+
+ if (__mode_ & ios_base::out) {
+ this->setp(__s.data(), __s.data() + __s.size());
+ if (__mode_ & ios_base::ate) {
+ this->pbump(__s.size());
+ }
+ }
+
+ if (__mode_ & ios_base::in) {
+ this->setg(__s.data(), __s.data(), __s.data() + __s.size());
+ }
+ }
+
+protected:
+ // [spanbuf.virtuals], overridden virtual functions
+
+ _LIBCPP_HIDE_FROM_ABI basic_streambuf<_CharT, _Traits>* setbuf(_CharT* __s, streamsize __n) override {
+ this->span(std::span<_CharT>(__s, __n));
+ return this;
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pos_type
+ seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __which = ios_base::in | ios_base::out) override {
+ const pos_type __error(off_type(-1));
+
+ if ((__which & ios_base::in) && (__which & ios_base::out) && (ios_base::cur == __way))
+ return __error;
+
+ off_type __baseoff = [this, __way, __which] {
+ switch (__way) {
+ case ios_base::beg:
+ return off_type(0);
+
+ case ios_base::cur:
+ if (__which & ios_base::out)
+ return off_type(this->pptr() - this->pbase());
+ return off_type(this->gptr() - this->eback());
+
+ case ios_base::end:
+ if ((__which & ios_base::out) && !(__which & ios_base::in))
+ return off_type(this->pptr() - this->pbase());
+ return off_type(__buf_.size());
+ }
+ }();
+
+ off_type __newoff;
+ if (__builtin_add_overflow(__baseoff, __off, &__newoff) || (__newoff < off_type(0)) ||
+ (std::cmp_greater(__newoff, __buf_.size())))
+ return __error;
+
+ if (__which & ios_base::in) {
+ if ((this->gptr() == nullptr) && (__newoff != off_type(0)))
+ return __error;
+ this->setg(this->eback(), this->eback() + __newoff, this->egptr());
+ }
+
+ if (__which & ios_base::out) {
+ if ((this->pptr() == nullptr) && (__newoff != off_type(0)))
+ return __error;
+ this->setp(this->pbase(), this->epptr());
+ this->pbump(__newoff);
+ }
+
+ return pos_type(__newoff);
+ }
+
+ _LIBCPP_HIDE_FROM_ABI pos_type seekpos(pos_type __sp,
+ ios_base::openmode __which = ios_base::in | ios_base::out) override {
+ return seekoff(off_type(__sp), ios_base::beg, __which);
+ }
+
+private:
+ ios_base::openmode __mode_; // exposition only
+ std::span<_CharT> __buf_; // exposition only
+};
+
+template <class _CharT, class _Traits>
+_LIBCPP_HIDE_FROM_ABI void swap(basic_spanbuf<_CharT, _Traits>& __x, basic_spanbuf<_CharT, _Traits>& __y) {
+ __x.swap(__y);
+}
+
+using std::spanbuf;
+# ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
+using std::wspanbuf;
+# endif
+
+// Class template basic_ispanstream [ispanstream]
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_ispanstream : public basic_istream<_CharT, _Traits> {
+public:
+ using char_type = _CharT;
+ using int_type = typename _Traits::int_type;
+ using pos_type = typename _Traits::pos_type;
+ using off_type = typename _Traits::off_type;
+ using traits_type = _Traits;
+
+ // [ispanstream.cons], constructors
+
+ _LIBCPP_HIDE_FROM_ABI explicit basic_ispanstream(std::span<_CharT> __s, ios_base::openmode __which = ios_base::in)
+ : basic_istream<_CharT, _Traits>(std::addressof(__sb_)),
+ __sb_(basic_spanbuf<_CharT, _Traits>(__s, __which | ios_base::in)) {}
+
+ basic_ispanstream(const basic_ispanstream&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI basic_ispanstream(basic_ispanstream&& __rhs)
+ : basic_istream<_CharT, _Traits>(std::move(__rhs)), __sb_(std::move(__rhs.__sb_)) {
+ basic_istream<_CharT, _Traits>::set_rdbuf(std::addressof(__sb_));
+ }
+
+ template <ranges::borrowed_range _ROSeq>
+ requires(!convertible_to<_ROSeq, std::span<_CharT>>) && convertible_to<_ROSeq, std::span<const _CharT>>
+ _LIBCPP_HIDE_FROM_ABI explicit basic_ispanstream(_ROSeq&& __s)
+ : basic_istream<_CharT, _Traits>(std::addressof(__sb_)) {
+ std::span<const _CharT> __sp(std::forward<_ROSeq>(__s));
+ this->span(std::span<_CharT>(std::span<_CharT>(const_cast<_CharT*>(__sp.data()), __sp.size())));
+ }
+
+ basic_ispanstream& operator=(const basic_ispanstream&) = delete;
+
+ _LIBCPP_HIDE_FROM_ABI basic_ispanstream& operator=(basic_ispanstream&& __rhs) {
+ basic_ispanstream __tmp{std::move(__rhs)};
+ this->swap(__tmp);
+ return *this;
+ }
+
+ // [ispanstream.swap], swap
+
+ _LIBCPP_HIDE_FROM_ABI void swap(basic_ispanstream& __rhs) {
+ basic_istream<_CharT, _Traits>::swap(__rhs);
+ __sb_.swap(__rhs.__sb_);
+ }
+
+ // [ispanstream.members], member functions
+
+ _LIBCPP...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/83541
More information about the libcxx-commits
mailing list