Reverted. (was Re: [PATCH v4] libstdc++: stringstream ctors from string_view [PR119741])
Jonathan Wakely
jwakely.gcc@gmail.com
Thu Jun 5 06:39:08 GMT 2025
There was no need to revert this, it wasn't breaking bootstrap, only
causing a handful of test failures.
The new wchar_t tests just need the same { dg-do run { target c++26 } }
directives as the char tests.
Dejagnu only looks for directives in the main file, not in included files.
On Thu, 5 Jun 2025, 04:23 Nathan Myers, <ncm@cantrip.org> wrote:
> On 6/4/25 20:30, H.J. Lu wrote:
> > On Wed, Jun 4, 2025 at 8:02 PM Jonathan Wakely <jwakely@redhat.com>
> wrote:
> >>
> >> On Thu, 29 May 2025 at 20:30, Nathan Myers <ncm@cantrip.org> wrote:
> >>>
> >>> Change in V4:
> >>> * Rename tests to string_view.cc
> >>> * Adapt tests to cons/wchar_t directories
> >>> * Define symbol __cpp_lib_sstream_from_string_view as 202406
> >>> * Define symbol __glibcxx_want_sstream_from_string_view before
> version.h
> >>> * Include version.h after other includes
> >>> * No include type_traits
> >>> * Drive-by comment moved to commit message
> >>> * Each `explicit` on its own line
> >>> * Run tests even when using old COW string
> >>>
> >>> Change in V3:
> >>> * Comment that p2495 specifies a drive-by constraint omitted as
> redundant
> >>> * Adjust whitespace to fit in 80 columns
> >>>
> >>> Change in V2:
> >>> * Apply all review comments
> >>> * Remove redundant drive-by "requires" on ctor from string allocator
> arg
> >>> * Check allocators are plumbed through
> >>
> >> Looks great now, thanks for iterating on it.
> >>
> >> Please push to trunk (you'll probably need to rebase first, which will
> >> have a merge conflict in bits/version.h but just regenerating it again
> >> will resolve that).
> >
> > On Fedora 42/x86-64, I got
> >
> > FAIL: 27_io/basic_istringstream/cons/wchar_t/string_view.cc
> > -std=gnu++17 (test for excess errors)
> > Excess errors:
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:39:
> > error: 'requires' only available with '-std=c++20' or '-fconcepts'
> > [-Wtemplate-body]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:39:
> > error: expected ',' before '{' token [-Wtemplate-body]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:39:
> > warning: 'static_assert' with non-string message only available with
> > '-std=c++2c' or '-std=gnu++2c' [-Wc++26-extensions]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:39:
> > error: expected primary-expression before '{' token [-Wtemplate-body]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:39:
> > error: expected ')' before '{' token [-Wtemplate-body]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:41:
> > error: 'requires' only available with '-std=c++20' or '-fconcepts'
> > [-Wtemplate-body]
> >
> /export/gnu/import/git/gitlab/x86-gcc-test/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/../char/string_view.cc:41:
> > error: expected ',' before '{' token [-Wtemplate-body]
>
> Reverted a31e76a2643.
>
> >>> -- >8 --
> >>>
> >>> Implement PR libstdc++/119741 (P2495R3).
> >>> Add constructors to stringbuf, stringstream, istringstream, and
> ostringstream,
> >>> and a matching overload of str(sv) in each, that take anything
> convertible to
> >>> a string_view in places where the existing ctors and function take a
> string.
> >>> Note this change omits the constraint applied to the istringstream
> constructor
> >>> from string cited as a "drive-by" in P2495R3, as we have determined it
> is
> >>> redundant.
> >>>
> >>> libstdc++-v3/ChangeLog:
> >>>
> >>> PR libstdc++/119741
> >>> * include/std/sstream: full implementation, really just
> >>> decls, requires clause and plumbing.
> >>> * include/bits/version.def, include/bits/version.h:
> >>> new preprocessor symbol
> >>> __cpp_lib_sstream_from_string_view.
> >>> * testsuite/27_io/basic_stringbuf/cons/char/string_view.cc:
> >>> New tests.
> >>> *
> testsuite/27_io/basic_istringstream/cons/char/string_view.cc:
> >>> New tests.
> >>> *
> testsuite/27_io/basic_ostringstream/cons/char/string_view.cc:
> >>> New tests.
> >>> * testsuite/27_io/basic_stringstream/cons/char/string_view.cc:
> >>> New tests.
> >>> * testsuite/27_io/basic_stringbuf/cons/wchar_t/string_view.cc:
> >>> New tests.
> >>> *
> testsuite/27_io/basic_istringstream/cons/wchar_t/string_view.cc:
> >>> New tests.
> >>> *
> testsuite/27_io/basic_ostringstream/cons/wchar_t/string_view.cc:
> >>> New tests.
> >>> *
> testsuite/27_io/basic_stringstream/cons/wchar_t/string_view.cc:
> >>> New tests.
> >>> ---
> >>> libstdc++-v3/include/bits/version.def | 11 +-
> >>> libstdc++-v3/include/bits/version.h | 10 +
> >>> libstdc++-v3/include/std/sstream | 198 +++++++++++++++--
> >>> .../cons/char/string_view.cc | 195 +++++++++++++++++
> >>> .../cons/wchar_t/string_view.cc | 3 +
> >>> .../cons/char/string_view.cc | 194 +++++++++++++++++
> >>> .../cons/wchar_t/string_view.cc | 3 +
> >>> .../basic_stringbuf/cons/char/string_view.cc | 205
> ++++++++++++++++++
> >>> .../cons/wchar_t/string_view.cc | 3 +
> >>> .../cons/char/string_view.cc | 204 +++++++++++++++++
> >>> .../cons/wchar_t/string_view.cc | 3 +
> >>> 11 files changed, 1010 insertions(+), 19 deletions(-)
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_istringstream/cons/char/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/char/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/wchar_t/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/char/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/wchar_t/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_stringstream/cons/char/string_view.cc
> >>> create mode 100644
> libstdc++-v3/testsuite/27_io/basic_stringstream/cons/wchar_t/string_view.cc
> >>>
> >>> diff --git a/libstdc++-v3/include/bits/version.def
> b/libstdc++-v3/include/bits/version.def
> >>> index 282667eabda..53bf72d95c2 100644
> >>> --- a/libstdc++-v3/include/bits/version.def
> >>> +++ b/libstdc++-v3/include/bits/version.def
> >>> @@ -649,7 +649,7 @@ ftms = {
> >>> };
> >>> values = {
> >>> v = 1;
> >>> - /* For when there's no gthread. */
> >>> + // For when there is no gthread.
> >>> cxxmin = 17;
> >>> hosted = yes;
> >>> gthread = no;
> >>> @@ -1945,6 +1945,15 @@ ftms = {
> >>> };
> >>> };
> >>>
> >>> +ftms = {
> >>> + name = sstream_from_string_view;
> >>> + values = {
> >>> + v = 202306;
> >>> + cxxmin = 26;
> >>> + hosted = yes;
> >>> + };
> >>> +};
> >>> +
> >>> // Standard test specifications.
> >>> stds[97] = ">= 199711L";
> >>> stds[03] = ">= 199711L";
> >>> diff --git a/libstdc++-v3/include/bits/version.h
> b/libstdc++-v3/include/bits/version.h
> >>> index bb7c0479c72..0b932183e5b 100644
> >>> --- a/libstdc++-v3/include/bits/version.h
> >>> +++ b/libstdc++-v3/include/bits/version.h
> >>> @@ -2174,4 +2174,14 @@
> >>> #endif /* !defined(__cpp_lib_modules) &&
> defined(__glibcxx_want_modules) */
> >>> #undef __glibcxx_want_modules
> >>>
> >>> +#if !defined(__cpp_lib_sstream_from_string_view)
> >>> +# if (__cplusplus >= 202306L) && _GLIBCXX_HOSTED
> >>> +# define __glibcxx_sstream_from_string_view 202306L
> >>> +# if defined(__glibcxx_want_all) ||
> defined(__glibcxx_want_sstream_from_string_view)
> >>> +# define __cpp_lib_sstream_from_string_view 202306L
> >>> +# endif
> >>> +# endif
> >>> +#endif /* !defined(__cpp_lib_sstream_from_string_view) &&
> defined(__glibcxx_want_sstream_from_string_view) */
> >>> +#undef __glibcxx_want_sstream_from_string_view
> >>> +
> >>> #undef __glibcxx_want_all
> >>> diff --git a/libstdc++-v3/include/std/sstream
> b/libstdc++-v3/include/std/sstream
> >>> index ad0c16a91e8..edef599bd6f 100644
> >>> --- a/libstdc++-v3/include/std/sstream
> >>> +++ b/libstdc++-v3/include/std/sstream
> >>> @@ -41,8 +41,12 @@
> >>>
> >>> #include <istream>
> >>> #include <ostream>
> >>> +
> >>> #include <bits/alloc_traits.h> // allocator_traits, __allocator_like
> >>>
> >>> +#define __glibcxx_want_sstream_from_string_view
> >>> +#include <bits/version.h>
> >>> +
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> # define _GLIBCXX_LVAL_REF_QUAL &
> >>> # define _GLIBCXX_SSTREAM_ALWAYS_INLINE
> >>> @@ -52,8 +56,6 @@
> >>> # define _GLIBCXX_SSTREAM_ALWAYS_INLINE
> [[__gnu__::__always_inline__]]
> >>> #endif
> >>>
> >>> -
> >>> -
> >>> namespace std _GLIBCXX_VISIBILITY(default)
> >>> {
> >>> _GLIBCXX_BEGIN_NAMESPACE_VERSION
> >>> @@ -159,6 +161,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> {
> __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> explicit
> >>> basic_stringbuf(const allocator_type& __a)
> >>> : basic_stringbuf(ios_base::in | std::ios_base::out, __a)
> >>> @@ -197,7 +200,36 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> | ios_base::out)
> >>> : basic_stringbuf(__s, __mode, allocator_type{})
> >>> { }
> >>> +#endif
> >>> +
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template<typename _Tp>
> >>> + explicit
> >>> + basic_stringbuf(const _Tp& __t,
> >>> + ios_base::openmode __mode = ios_base::in | ios_base::out)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_stringbuf(__t, __mode, allocator_type{})
> >>> + { }
> >>> +
> >>> + template<typename _Tp>
> >>> + basic_stringbuf(const _Tp& __t, const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_stringbuf(__t, ios_base::in | ios_base::out, __a)
> >>> + { }
> >>>
> >>> + template<typename _Tp>
> >>> + basic_stringbuf(const _Tp& __t, ios_base::openmode __mode,
> >>> + const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : _M_string(__t, __a)
> >>> + { _M_stringbuf_init(__mode); }
> >>> +#endif // C++26
> >>> +
> >>> +#if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type&
> __a)
> >>> : basic_stringbuf(std::move(__rhs), __a, __xfer_bufptrs(__rhs,
> this))
> >>> {
> __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
> >>> @@ -262,6 +294,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> #if __cplusplus > 201703L
> >>> #if _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> _GLIBCXX_NODISCARD
> >>> basic_string<_CharT, _Traits, _SAlloc>
> >>> @@ -317,6 +350,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> requires (!is_same_v<_SAlloc, _Alloc>)
> >>> void
> >>> @@ -335,6 +369,19 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> }
> >>> #endif
> >>>
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template <typename _Tp>
> >>> + void
> >>> + str(const _Tp& __t)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + {
> >>> + basic_string_view<_CharT, _Traits> __sv{__t};
> >>> + _M_string = __sv;
> >>> + _M_stringbuf_init(_M_mode);
> >>> + }
> >>> +#endif // C++26
> >>> +
> >>> protected:
> >>> // Common initialization code goes here.
> >>> void
> >>> @@ -521,6 +568,8 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> { }
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> +
> >>> // The move constructor initializes an __xfer_bufptrs
> temporary then
> >>> // delegates to this constructor to performs moves during its
> lifetime.
> >>> basic_stringbuf(basic_stringbuf&& __rhs, const allocator_type&
> __a,
> >>> @@ -584,7 +633,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> */
> >>> basic_istringstream()
> >>> : __istream_type(), _M_stringbuf(ios_base::in)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an empty string buffer.
> >>> @@ -601,7 +650,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> explicit
> >>> basic_istringstream(ios_base::openmode __mode)
> >>> : __istream_type(), _M_stringbuf(__mode | ios_base::in)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an existing string buffer.
> >>> @@ -620,7 +669,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_istringstream(const __string_type& __str,
> >>> ios_base::openmode __mode = ios_base::in)
> >>> : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief The destructor does nothing.
> >>> @@ -637,9 +686,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_istringstream(basic_istringstream&& __rhs)
> >>> : __istream_type(std::move(__rhs)),
> >>> _M_stringbuf(std::move(__rhs._M_stringbuf))
> >>> - { __istream_type::set_rdbuf(&_M_stringbuf); }
> >>> + { __istream_type::set_rdbuf(std::__addressof(_M_stringbuf)); }
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> basic_istringstream(ios_base::openmode __mode, const
> allocator_type& __a)
> >>> : __istream_type(), _M_stringbuf(__mode | ios_base::in, __a)
> >>> { this->init(std::__addressof(_M_stringbuf)); }
> >>> @@ -671,6 +721,32 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> { }
> >>> #endif // C++20
> >>>
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template <typename _Tp>
> >>> + explicit
> >>> + basic_istringstream(const _Tp& __t,
> >>> + ios_base::openmode __mode = ios_base::in)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_istringstream(__t, __mode, allocator_type{})
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_istringstream(const _Tp& __t, const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_istringstream(__t, ios_base::in, __a)
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_istringstream(const _Tp& __t, ios_base::openmode __mode,
> >>> + const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : __istream_type(), _M_stringbuf(__t, __mode | ios_base::in,
> __a)
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>> +#endif // C++26
> >>> +
> >>> // 27.8.3.2 Assign and swap:
> >>>
> >>> basic_istringstream&
> >>> @@ -702,7 +778,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> _GLIBCXX_NODISCARD
> >>> __stringbuf_type*
> >>> rdbuf() const
> >>> - { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
> >>> + { return
> const_cast<__stringbuf_type*>(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Copying out the string buffer.
> >>> @@ -716,6 +792,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> #if __cplusplus > 201703L
> >>> #if _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> _GLIBCXX_NODISCARD
> >>> basic_string<_CharT, _Traits, _SAlloc>
> >>> @@ -747,6 +824,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> requires (!is_same_v<_SAlloc, _Alloc>)
> >>> void
> >>> @@ -758,6 +836,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> str(__string_type&& __s)
> >>> { _M_stringbuf.str(std::move(__s)); }
> >>> #endif
> >>> +
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template<typename _Tp>
> >>> + void
> >>> + str(const _Tp& __t)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + { _M_stringbuf.str(__t); }
> >>> +#endif // C++26
> >>> };
> >>>
> >>>
> >>> @@ -812,7 +899,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> */
> >>> basic_ostringstream()
> >>> : __ostream_type(), _M_stringbuf(ios_base::out)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an empty string buffer.
> >>> @@ -829,7 +916,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> explicit
> >>> basic_ostringstream(ios_base::openmode __mode)
> >>> : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an existing string buffer.
> >>> @@ -848,7 +935,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_ostringstream(const __string_type& __str,
> >>> ios_base::openmode __mode = ios_base::out)
> >>> : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief The destructor does nothing.
> >>> @@ -865,9 +952,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_ostringstream(basic_ostringstream&& __rhs)
> >>> : __ostream_type(std::move(__rhs)),
> >>> _M_stringbuf(std::move(__rhs._M_stringbuf))
> >>> - { __ostream_type::set_rdbuf(&_M_stringbuf); }
> >>> + { __ostream_type::set_rdbuf(std::__addressof(_M_stringbuf)); }
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> basic_ostringstream(ios_base::openmode __mode, const
> allocator_type& __a)
> >>> : __ostream_type(), _M_stringbuf(__mode | ios_base::out, __a)
> >>> { this->init(std::__addressof(_M_stringbuf)); }
> >>> @@ -899,6 +987,32 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> { }
> >>> #endif // C++20
> >>>
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template <typename _Tp>
> >>> + explicit
> >>> + basic_ostringstream(
> >>> + const _Tp& __t, ios_base::openmode __mode = ios_base::out)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_ostringstream(__t, __mode, allocator_type{})
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_ostringstream(const _Tp& __t, const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_ostringstream(__t, ios_base::out, __a)
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_ostringstream(const _Tp& __t, ios_base::openmode __mode,
> >>> + const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : __ostream_type(), _M_stringbuf(__t, __mode | ios_base::out,
> __a)
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>> +#endif // C++26
> >>> +
> >>> // 27.8.3.2 Assign and swap:
> >>>
> >>> basic_ostringstream&
> >>> @@ -930,7 +1044,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> _GLIBCXX_NODISCARD
> >>> __stringbuf_type*
> >>> rdbuf() const
> >>> - { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
> >>> + { return
> const_cast<__stringbuf_type*>(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Copying out the string buffer.
> >>> @@ -944,6 +1058,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> #if __cplusplus > 201703L
> >>> #if _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> _GLIBCXX_NODISCARD
> >>> basic_string<_CharT, _Traits, _SAlloc>
> >>> @@ -975,6 +1090,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> requires (!is_same_v<_SAlloc, _Alloc>)
> >>> void
> >>> @@ -986,6 +1102,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> str(__string_type&& __s)
> >>> { _M_stringbuf.str(std::move(__s)); }
> >>> #endif
> >>> +
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template<typename _Tp>
> >>> + void
> >>> + str(const _Tp& __t)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + { _M_stringbuf.str(__t); }
> >>> +#endif // C++26
> >>> };
> >>>
> >>>
> >>> @@ -1040,7 +1165,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> */
> >>> basic_stringstream()
> >>> : __iostream_type(), _M_stringbuf(ios_base::out | ios_base::in)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an empty string buffer.
> >>> @@ -1055,7 +1180,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> explicit
> >>> basic_stringstream(ios_base::openmode __m)
> >>> : __iostream_type(), _M_stringbuf(__m)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Starts with an existing string buffer.
> >>> @@ -1072,7 +1197,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_stringstream(const __string_type& __str,
> >>> ios_base::openmode __m = ios_base::out |
> ios_base::in)
> >>> : __iostream_type(), _M_stringbuf(__str, __m)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief The destructor does nothing.
> >>> @@ -1089,12 +1214,13 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> basic_stringstream(basic_stringstream&& __rhs)
> >>> : __iostream_type(std::move(__rhs)),
> >>> _M_stringbuf(std::move(__rhs._M_stringbuf))
> >>> - { __iostream_type::set_rdbuf(&_M_stringbuf); }
> >>> + { __iostream_type::set_rdbuf(std::__addressof(_M_stringbuf)); }
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> + // P0408 Efficient access to basic_stringbuf buffer
> >>> basic_stringstream(ios_base::openmode __mode, const
> allocator_type& __a)
> >>> : __iostream_type(), _M_stringbuf(__mode, __a)
> >>> - { this->init(&_M_stringbuf); }
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>>
> >>> explicit
> >>> basic_stringstream(__string_type&& __str,
> >>> @@ -1125,6 +1251,31 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> { }
> >>> #endif // C++20
> >>>
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template <typename _Tp>
> >>> + explicit
> >>> + basic_stringstream(const _Tp& __t,
> >>> + ios_base::openmode __mode = ios_base::in | ios_base::out)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_stringstream(__t, __mode, allocator_type{})
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_stringstream(const _Tp& __t, const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + : basic_stringstream(__t, ios_base::in | ios_base::out, __a)
> >>> + { }
> >>> +
> >>> + template <typename _Tp>
> >>> + basic_stringstream(const _Tp& __t, ios_base::openmode __mode,
> >>> + const allocator_type& __a)
> >>> + requires (is_convertible_v<const _Tp&,
> basic_string_view<_CharT, _Traits>>)
> >>> + : __iostream_type(), _M_stringbuf(__t, __mode, __a)
> >>> + { this->init(std::__addressof(_M_stringbuf)); }
> >>> +#endif // C++26
> >>> +
> >>> // 27.8.3.2 Assign and swap:
> >>>
> >>> basic_stringstream&
> >>> @@ -1156,7 +1307,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> _GLIBCXX_NODISCARD
> >>> __stringbuf_type*
> >>> rdbuf() const
> >>> - { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
> >>> + { return
> const_cast<__stringbuf_type*>(std::__addressof(_M_stringbuf)); }
> >>>
> >>> /**
> >>> * @brief Copying out the string buffer.
> >>> @@ -1170,6 +1321,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> #if __cplusplus > 201703L
> >>> #if _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> _GLIBCXX_NODISCARD
> >>> basic_string<_CharT, _Traits, _SAlloc>
> >>> @@ -1201,6 +1353,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>>
> >>> #if __cplusplus > 201703L && _GLIBCXX_USE_CXX11_ABI
> >>> #if __cpp_concepts
> >>> + // P0407 Allocator-aware basic_streambuf
> >>> template<__allocator_like _SAlloc>
> >>> requires (!is_same_v<_SAlloc, _Alloc>)
> >>> void
> >>> @@ -1212,6 +1365,15 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
> >>> str(__string_type&& __s)
> >>> { _M_stringbuf.str(std::move(__s)); }
> >>> #endif
> >>> +
> >>> +#ifdef __cpp_lib_sstream_from_string_view
> >>> + template<typename _Tp>
> >>> + void
> >>> + str(const _Tp& __t)
> >>> + requires (is_convertible_v<const _Tp&,
> >>> + basic_string_view<_CharT, _Traits>>)
> >>> + { _M_stringbuf.str(__t); }
> >>> +#endif // C++26
> >>> };
> >>>
> >>> #if __cplusplus >= 201103L
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/char/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/char/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..27f65aa9437
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/char/string_view.cc
> >>> @@ -0,0 +1,195 @@
> >>> +// C++26 [istringstream.general]
> >>> +
> >>> +// { dg-do run { target c++26 } }
> >>> +
> >>> +#include <sstream>
> >>> +#include <string>
> >>> +#include <string_view>
> >>> +#include <testsuite_allocator.h>
> >>> +#include <testsuite_hooks.h>
> >>> +
> >>> +// Check C++26 P2495 istringstream ctors and members str(s) that
> accept a
> >>> +// string_view, or anything convertible to a string_view, in place of
> a
> >>> +// string object. Mostly just verify plumbing.
> >>> +
> >>> +#ifndef C
> >>> +# define C char
> >>> +# define L(a) a
> >>> +#endif
> >>> +
> >>> +using string = std::basic_string<C>;
> >>> +using string_view = std::basic_string_view<C>;
> >>> +using istringstream = std::basic_istringstream<C>;
> >>> +
> >>> +struct convertible_to_string_view {
> >>> + string s;
> >>> + operator string_view() const { return s; }
> >>> +};
> >>> +
> >>> +const string str(L("This is a test string"));
> >>> +convertible_to_string_view cstr{str}; // a copy
> >>> +const convertible_to_string_view ccstr{str}; // another copy
> >>> +
> >>> +template <typename istringstream = std::basic_istringstream<C>>
> >>> +void
> >>> +test01()
> >>> +{
> >>> + // Test C++26 constructor and str(s) taking a generalized
> string_view
> >>> +
> >>> + static_assert(! requires { istringstream(1); },
> >>> + "istringstream ctor should reject what cannot be converted to a
> string_view");
> >>> + static_assert(! requires { istringstream().str(1); },
> >>> + "istringstream::str(s) should reject what cannot be converted
> to a string_view");
> >>> +
> >>> + static_assert(!std::is_convertible_v<string_view, istringstream>,
> >>> + "istringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<const string_view,
> istringstream>,
> >>> + "istringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<convertible_to_string_view,
> istringstream>,
> >>> + "istringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> + static_assert(!std::is_convertible_v<const
> convertible_to_string_view, istringstream>,
> >>> + "istringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> +
> >>> + {
> >>> + istringstream istr(cstr);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + istringstream istr(ccstr);
> >>> + VERIFY( istr.str() == ccstr.s );
> >>> + VERIFY( istr.get() == ccstr.s[0] );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios_base::in);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') != 'X' );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios_base::out);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') == 'X' );
> >>> + }
> >>> +}
> >>> +
> >>> +void
> >>> +test02()
> >>> +{
> >>> + // Test various C++26 constructors taking string views
> >>> + // and mix of other arguments
> >>> +
> >>> + auto const mode = std::ios_base::in | std::ios_base::out;
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_istringstream(const T&, ios_base::openmode, const
> allocator_type&)
> >>> +
> >>> + istringstream::allocator_type a;
> >>> + {
> >>> + istringstream istr(cstr, mode, a); // ={} checks for
> non-explicit ctor
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios::in, a);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') != 'X' );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios::out, a);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') == 'X' );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_istringstream(const T&, ios_base::openmode)
> >>> + {
> >>> + istringstream istr(cstr, mode);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') == 'X' );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios::in);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') != 'X' );
> >>> + }
> >>> + {
> >>> + istringstream istr(cstr, std::ios::out);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') == 'X' );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // explicit
> >>> + // basic_istringstream(const T&, ios_base::openmode =
> ios_base::in)
> >>> +
> >>> + istringstream istr(cstr);
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') != 'X' );
> >>> + }
> >>> +}
> >>> +
> >>> +using alloc_type = __gnu_test::uneq_allocator<C>;
> >>> +
> >>> +template<typename Alloc, typename CC = typename Alloc::value_type>
> >>> + using istringstream_with_alloc
> >>> + = std::basic_istringstream<CC, std::char_traits<CC>, Alloc>;
> >>> +
> >>> +void test03()
> >>> +{
> >>> + alloc_type a{1};
> >>> + {
> >>> + istringstream_with_alloc<alloc_type> istr(cstr, a);
> >>> + VERIFY( istr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{istr.str()} == cstr );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + istringstream_with_alloc<alloc_type> istr(cstr, std::ios::in, a);
> >>> + VERIFY( istr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{istr.str()} == cstr );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') != 'X' );
> >>> + }
> >>> + {
> >>> + istringstream_with_alloc<alloc_type> istr(cstr, std::ios::out, a);
> >>> + VERIFY( istr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{istr.str()} == cstr );
> >>> + VERIFY( istr.get() == cstr.s[0] );
> >>> + VERIFY( istr.rdbuf()->sputc('X') == 'X' );
> >>> + }
> >>> +}
> >>> +
> >>> +void test04()
> >>> +{
> >>> + {
> >>> + istringstream istr;
> >>> + istr.str( cstr );
> >>> + VERIFY( istr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + istringstream istr;
> >>> + istr.str( ccstr );
> >>> + VERIFY( istr.str() == ccstr.s );
> >>> + }
> >>> +}
> >>> +
> >>> +int
> >>> +main()
> >>> +{
> >>> + test01();
> >>> + test02();
> >>> + test03();
> >>> + test04();
> >>> +}
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..cfb73c4c510
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_istringstream/cons/wchar_t/string_view.cc
> >>> @@ -0,0 +1,3 @@
> >>> +#define C wchar_t
> >>> +#define L(a) L##a
> >>> +#include "../char/string_view.cc"
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/char/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/char/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..731e97e4aa2
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/char/string_view.cc
> >>> @@ -0,0 +1,194 @@
> >>> +// C++26 [ostringstream.general]
> >>> +
> >>> +// { dg-do run { target c++26 } }
> >>> +
> >>> +#include <sstream>
> >>> +#include <string>
> >>> +#include <string_view>
> >>> +#include <testsuite_allocator.h>
> >>> +#include <testsuite_hooks.h>
> >>> +
> >>> +// Check C++26 P2495 ostringstream ctors and members str(s) that
> accept a
> >>> +// string_view, or anything convertible to a string_view, in place of
> a
> >>> +// string object. Mostly just verify plumbing.
> >>> +
> >>> +#ifndef C
> >>> +# define C char
> >>> +# define L(a) a
> >>> +#endif
> >>> +
> >>> +using string = std::basic_string<C>;
> >>> +using string_view = std::basic_string_view<C>;
> >>> +using ostringstream = std::basic_ostringstream<C>;
> >>> +
> >>> +struct convertible_to_string_view {
> >>> + string s;
> >>> + operator string_view() const { return s; }
> >>> +};
> >>> +
> >>> +const string str(L("This is a test string"));
> >>> +convertible_to_string_view cstr{str}; // a copy
> >>> +const convertible_to_string_view ccstr{str}; // another copy
> >>> +
> >>> +template <typename ostringstream = std::basic_ostringstream<C>>
> >>> +void
> >>> +test01()
> >>> +{
> >>> + // Test C++26 constructor and str(s) taking a generalized
> string_view
> >>> +
> >>> + static_assert(! requires { ostringstream(1); },
> >>> + "ostringstream ctor should reject what cannot be converted to a
> string_view");
> >>> + static_assert(! requires { ostringstream().str(1); },
> >>> + "ostringstream::str(s) should reject what cannot be converted
> to a string_view");
> >>> +
> >>> + static_assert(!std::is_convertible_v<string_view, ostringstream>,
> >>> + "ostringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<const string_view,
> ostringstream>,
> >>> + "ostringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<convertible_to_string_view,
> ostringstream>,
> >>> + "ostringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> + static_assert(!std::is_convertible_v<const
> convertible_to_string_view, ostringstream>,
> >>> + "ostringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> +
> >>> + {
> >>> + ostringstream ostrstr(cstr);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(ccstr);
> >>> + VERIFY( ostrstr.str() == ccstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios_base::in);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() == cstr.s[0]);
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios_base::out);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> +}
> >>> +
> >>> +void
> >>> +test02()
> >>> +{
> >>> + // Test plumbing of C++26 various constructors taking string views
> >>> +
> >>> + auto const mode = std::ios_base::in | std::ios_base::out;
> >>> +
> >>> + {
> >>> + ostringstream::allocator_type a;
> >>> + // template <typename T>
> >>> + // basic_ostringstream(const T&, ios_base::openmode, const
> allocator_type&)
> >>> + {
> >>> + ostringstream ostrstr(cstr, mode, a); // ={} checks for
> non-explicit ctor
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios::in, a);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() == cstr.s[0]);
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios::out, a);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_ostringstream(const T&, ios_base::openmode)
> >>> + {
> >>> + ostringstream ostrstr(cstr, mode);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() == cstr.s[0]);
> >>> + VERIFY( ostrstr.put('Y').good() );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios::in);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() == cstr.s[0]);
> >>> + VERIFY( ostrstr.put('X').good() );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr(cstr, std::ios::out);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // explicit
> >>> + // basic_ostringstream(const T&, ios_base::openmode =
> ios_base::out)
> >>> +
> >>> + ostringstream ostrstr(cstr);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('Y').good() );
> >>> + }
> >>> +}
> >>> +
> >>> +using alloc_type = __gnu_test::uneq_allocator<C>;
> >>> +
> >>> +template<typename Alloc, typename CC = typename Alloc::value_type>
> >>> + using ostringstream_with_alloc
> >>> + = std::basic_ostringstream<CC, std::char_traits<CC>, Alloc>;
> >>> +
> >>> +void test03()
> >>> +{
> >>> + alloc_type a{1};
> >>> + {
> >>> + ostringstream_with_alloc<alloc_type> ostrstr(cstr, a);
> >>> + VERIFY( ostrstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{ostrstr.str()} == cstr );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('X').good() );
> >>> + }
> >>> + {
> >>> + ostringstream_with_alloc<alloc_type> ostrstr(cstr, std::ios::in,
> a);
> >>> + VERIFY( ostrstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{ostrstr.str()} == cstr );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() == cstr.s[0]);
> >>> + VERIFY( ostrstr.put('X').good() );
> >>> + }
> >>> + {
> >>> + ostringstream_with_alloc<alloc_type> ostrstr(cstr, std::ios::out,
> a);
> >>> + VERIFY( ostrstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{ostrstr.str()} == cstr );
> >>> + VERIFY( ostrstr.rdbuf()->sgetc() ==
> ostringstream::traits_type::eof() );
> >>> + VERIFY( ostrstr.put('Y').rdstate() == ostrstr.goodbit );
> >>> + }
> >>> +}
> >>> +
> >>> +void test04()
> >>> +{
> >>> + {
> >>> + ostringstream ostrstr;
> >>> + ostrstr.str(cstr);
> >>> + VERIFY( ostrstr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + ostringstream ostrstr;
> >>> + ostrstr.str(ccstr);
> >>> + VERIFY( ostrstr.str() == ccstr.s );
> >>> + }
> >>> +}
> >>> +
> >>> +int
> >>> +main()
> >>> +{
> >>> + test01();
> >>> + test02();
> >>> + test03();
> >>> + test04();
> >>> +}
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/wchar_t/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/wchar_t/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..cfb73c4c510
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_ostringstream/cons/wchar_t/string_view.cc
> >>> @@ -0,0 +1,3 @@
> >>> +#define C wchar_t
> >>> +#define L(a) L##a
> >>> +#include "../char/string_view.cc"
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/char/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/char/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..7843269c48f
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/char/string_view.cc
> >>> @@ -0,0 +1,205 @@
> >>> +// C++26 31.8.2.1 [stringbuf.general]
> >>> +
> >>> +// { dg-do run { target c++26 } }
> >>> +
> >>> +#include <sstream>
> >>> +#include <string>
> >>> +#include <string_view>
> >>> +#include <testsuite_allocator.h>
> >>> +#include <testsuite_hooks.h>
> >>> +
> >>> +// Check C++26 P2495 stringbuf ctors and members str(s) that accept a
> >>> +// string_view, or anything convertible to a string_view, in place of
> a
> >>> +// string object.
> >>> +
> >>> +#ifndef C
> >>> +# define C char
> >>> +# define L(a) a
> >>> +#endif
> >>> +
> >>> +using string = std::basic_string<C>;
> >>> +using string_view = std::basic_string_view<C>;
> >>> +using stringbuf = std::basic_stringbuf<C>;
> >>> +
> >>> +struct convertible_to_string_view {
> >>> + string s;
> >>> + operator string_view() const { return s; }
> >>> +};
> >>> +
> >>> +const string str(L("This is a test string"));
> >>> +convertible_to_string_view cstr{str}; // a copy
> >>> +const convertible_to_string_view ccstr{str}; // another copy
> >>> +
> >>> +template <typename stringbuf = std::basic_stringbuf<C>>
> >>> +void
> >>> +test01()
> >>> +{
> >>> + // Test C++26 constructor and str(s) taking a generalized
> string_view
> >>> +
> >>> + static_assert(! requires { stringbuf(1); },
> >>> + "stringbuf ctor should reject what cannot be converted to a
> string_view");
> >>> + static_assert(! requires { stringbuf().str(1); },
> >>> + "stringbuf::str(s) should reject what cannot be converted to a
> string_view");
> >>> +
> >>> + static_assert(!std::is_convertible_v<string_view, stringbuf>,
> >>> + "stringbuf(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<const string_view, stringbuf>,
> >>> + "stringbuf(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<convertible_to_string_view,
> stringbuf>,
> >>> + "stringbuf(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> + static_assert(
> >>> + !std::is_convertible_v<const convertible_to_string_view,
> stringbuf>,
> >>> + "stringbuf(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> +
> >>> + {
> >>> + stringbuf sbuf(cstr);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(ccstr);
> >>> + VERIFY( sbuf.str() == ccstr.s );
> >>> + VERIFY( sbuf.sgetc() == ccstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios_base::in);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + VERIFY( sbuf.sputc('X') == stringbuf::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(ccstr, std::ios_base::in);
> >>> + VERIFY( sbuf.str() == ccstr.s );
> >>> + VERIFY( sbuf.sgetc() == ccstr.s[0] );
> >>> + VERIFY( sbuf.sputc('X') == stringbuf::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios_base::out);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sputc('Y') == 'Y' );
> >>> + VERIFY( sbuf.sgetc() == stringbuf::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(ccstr, std::ios_base::out);
> >>> + VERIFY( sbuf.str() == ccstr.s );
> >>> + VERIFY( sbuf.sputc('Y') == 'Y' );
> >>> + VERIFY( sbuf.sgetc() == stringbuf::traits_type::eof() );
> >>> + }
> >>> +}
> >>> +
> >>> +void
> >>> +test02()
> >>> +{
> >>> + // Test C++26 constructors taking string views using different
> allocators
> >>> +
> >>> + auto const mode = std::ios_base::in | std::ios_base::out;
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_stringbuf(const T&, ios_base::openmode, const
> allocator_type&)
> >>> +
> >>> + stringbuf::allocator_type a;
> >>> + {
> >>> + stringbuf sbuf(cstr, mode, a); // ={} checks for non-explicit
> ctor
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios::in, a);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + VERIFY( sbuf.sputc('X') == stringbuf::traits_type::eof() );
> >>> + }
> >>> +
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios::out, a);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sputc('X') == 'X' );
> >>> + VERIFY( sbuf.sgetc() == stringbuf::traits_type::eof() );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_stringbuf(const T&, ios_base::openmode)
> >>> + {
> >>> + stringbuf sbuf(cstr, mode);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios::in);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + VERIFY( sbuf.sputc('X') == stringbuf::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf(cstr, std::ios::out);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sputc('X') == 'X' );
> >>> + VERIFY( sbuf.sgetc() == stringbuf::traits_type::eof() );
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // explicit
> >>> + // basic_stringbuf(const T&, ios_base::openmode =
> ios_base::in|ios_base::out)
> >>> +
> >>> + stringbuf sbuf(cstr);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + }
> >>> +}
> >>> +
> >>> +using alloc_type = __gnu_test::uneq_allocator<C>;
> >>> +
> >>> +template<typename Alloc, typename CC = typename Alloc::value_type>
> >>> + using stringbuf_with_alloc
> >>> + = std::basic_stringbuf<CC, std::char_traits<CC>, Alloc>;
> >>> +
> >>> +void test03()
> >>> +{
> >>> + alloc_type a{1};
> >>> + {
> >>> + stringbuf_with_alloc<alloc_type> sbuf(cstr, a);
> >>> + VERIFY( sbuf.get_allocator() == a );
> >>> + VERIFY( string_view{sbuf.str()} == cstr );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringbuf_with_alloc<alloc_type> sbuf(cstr, std::ios::in, a);
> >>> + VERIFY( sbuf.get_allocator() == a );
> >>> + VERIFY( string_view{sbuf.str()} == cstr );
> >>> + VERIFY( sbuf.sgetc() == cstr.s[0] );
> >>> + VERIFY( sbuf.sputc('X') == stringbuf::traits_type::eof() );
> >>> + }
> >>> + {
> >>> + stringbuf_with_alloc<alloc_type> sbuf(cstr, std::ios::out, a);
> >>> + VERIFY( sbuf.get_allocator() == a );
> >>> + VERIFY( string_view{sbuf.str()} == cstr );
> >>> + VERIFY( sbuf.sputc('X') == 'X' );
> >>> + VERIFY( sbuf.sgetc() == stringbuf::traits_type::eof() );
> >>> + }
> >>> +}
> >>> +
> >>> +void test04()
> >>> +{
> >>> + {
> >>> + stringbuf sbuf;
> >>> + sbuf.str(cstr);
> >>> + VERIFY( sbuf.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + stringbuf sbuf;
> >>> + sbuf.str(ccstr);
> >>> + VERIFY( sbuf.str() == ccstr.s );
> >>> + }
> >>> +}
> >>> +
> >>> +int
> >>> +main()
> >>> +{
> >>> + test01();
> >>> + test02();
> >>> + test03();
> >>> + test04();
> >>> +}
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/wchar_t/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/wchar_t/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..cfb73c4c510
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_stringbuf/cons/wchar_t/string_view.cc
> >>> @@ -0,0 +1,3 @@
> >>> +#define C wchar_t
> >>> +#define L(a) L##a
> >>> +#include "../char/string_view.cc"
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/char/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/char/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..72085230442
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/char/string_view.cc
> >>> @@ -0,0 +1,204 @@
> >>> +// C++26 31.8.2.1 [stringstream.general]
> >>> +
> >>> +// { dg-do run { target c++26 } }
> >>> +
> >>> +#include <sstream>
> >>> +#include <string>
> >>> +#include <string_view>
> >>> +#include <testsuite_allocator.h>
> >>> +#include <testsuite_hooks.h>
> >>> +
> >>> +// Check C++26 P2495 stringstream ctors and members str(s) that
> accept a
> >>> +// string_view, or anything convertible to a string_view, in place of
> a
> >>> +// string object. Mostly just verify plumbing.
> >>> +
> >>> +#ifndef C
> >>> +# define C char
> >>> +# define L(a) a
> >>> +#endif
> >>> +
> >>> +using string = std::basic_string<C>;
> >>> +using string_view = std::basic_string_view<C>;
> >>> +using stringstream = std::basic_stringstream<C>;
> >>> +
> >>> +struct convertible_to_string_view {
> >>> + string s;
> >>> + operator string_view() const { return s; }
> >>> +};
> >>> +
> >>> +const string str(L("This is a test string"));
> >>> +convertible_to_string_view cstr{str}; // a copy
> >>> +const convertible_to_string_view ccstr{str}; // another copy
> >>> +
> >>> +template <typename stringstream = std::basic_stringstream<C>>
> >>> +void
> >>> +test01()
> >>> +{
> >>> + // Test C++26 constructor and str(s) taking a generalized
> string_view
> >>> +
> >>> + static_assert(! requires { stringstream(1); },
> >>> + "stringstream ctor should reject what cannot be converted to a
> string_view");
> >>> + static_assert(! requires { stringstream().str(1); },
> >>> + "stringstream::str(s) should reject what cannot be converted to
> a string_view");
> >>> +
> >>> + static_assert(!std::is_convertible_v<string_view, stringstream>,
> >>> + "stringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<const string_view,
> stringstream>,
> >>> + "stringstream(string_view, ios::openmode) is explicit");
> >>> + static_assert(!std::is_convertible_v<convertible_to_string_view,
> stringstream>,
> >>> + "stringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> + static_assert(!std::is_convertible_v<const
> convertible_to_string_view, stringstream>,
> >>> + "stringstream(convertible_to_string_view, ios::openmode) is
> explicit");
> >>> +
> >>> + {
> >>> + stringstream strstr(cstr);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringstream strstr(ccstr);
> >>> + VERIFY( strstr.str() == ccstr.s );
> >>> + VERIFY( strstr.get() == ccstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios_base::in);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').rdstate() == strstr.badbit );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios_base::out);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.put('Y').good() );
> >>> + VERIFY( strstr.get() == stringstream::traits_type::eof());
> >>> + }
> >>> +}
> >>> +
> >>> +void
> >>> +test02()
> >>> +{
> >>> + // Test C++26 various constructors taking string views
> >>> +
> >>> + auto const mode = std::ios_base::in | std::ios_base::out;
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_stringstream(const T&, ios_base::openmode, const
> allocator_type&)
> >>> +
> >>> + stringstream::allocator_type a;
> >>> + {
> >>> + stringstream strstr(cstr, mode, a); // ={} checks for
> non-explicit ctor
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios::in, a);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').rdstate() == strstr.badbit );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios::out, a);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.put('X').good() );
> >>> + VERIFY( strstr.get() == stringstream::traits_type::eof());
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // basic_stringstream(const T&, ios_base::openmode)
> >>> +
> >>> + {
> >>> + stringstream strstr(cstr, mode);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').good() );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios::in);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').rdstate() == strstr.badbit );
> >>> + }
> >>> + {
> >>> + stringstream strstr(cstr, std::ios::out);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.put('X').good() );
> >>> + VERIFY( strstr.get() == stringstream::traits_type::eof());
> >>> + }
> >>> + }
> >>> +
> >>> + {
> >>> + // template <typename T>
> >>> + // explicit
> >>> + // basic_stringstream(const T&, ios_base::openmode =
> ios_base::in|ios_base::out)
> >>> +
> >>> + stringstream strstr(cstr);
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').good() );
> >>> + }
> >>> +}
> >>> +
> >>> +// A minimal allocator with no default constructor
> >>> +template<typename T>
> >>> + struct NoDefaultCons : __gnu_test::SimpleAllocator<T>
> >>> + {
> >>> + using __gnu_test::SimpleAllocator<T>::SimpleAllocator;
> >>> + NoDefaultCons() = delete;
> >>> + NoDefaultCons(int) { }
> >>> + };
> >>> +
> >>> +using alloc_type = __gnu_test::uneq_allocator<C>;
> >>> +
> >>> +template<typename Alloc, typename CC = typename Alloc::value_type>
> >>> + using stringstream_with_alloc
> >>> + = std::basic_stringstream<CC, std::char_traits<CC>, Alloc>;
> >>> +
> >>> +void test03()
> >>> +{
> >>> + alloc_type a{1};
> >>> + {
> >>> + stringstream_with_alloc<alloc_type> strstr(cstr, a);
> >>> + VERIFY( strstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{strstr.str()} == cstr );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + }
> >>> + {
> >>> + stringstream_with_alloc<alloc_type> strstr(cstr, std::ios::in, a);
> >>> + VERIFY( strstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{strstr.str()} == cstr );
> >>> + VERIFY( strstr.get() == cstr.s[0] );
> >>> + VERIFY( strstr.put('X').rdstate() == strstr.badbit );
> >>> + }
> >>> + {
> >>> + stringstream_with_alloc<alloc_type> strstr(cstr, std::ios::out,
> a);
> >>> + VERIFY( strstr.rdbuf()->get_allocator() == a );
> >>> + VERIFY( string_view{strstr.str()} == cstr );
> >>> + VERIFY( strstr.put('X').good() );
> >>> + VERIFY( strstr.get() == stringstream::traits_type::eof());
> >>> + }
> >>> +}
> >>> +
> >>> +void test04()
> >>> +{
> >>> + {
> >>> + stringstream strstr;
> >>> + strstr.str( cstr );
> >>> + VERIFY( strstr.str() == cstr.s );
> >>> + }
> >>> + {
> >>> + stringstream strstr;
> >>> + strstr.str( ccstr );
> >>> + VERIFY( strstr.str() == ccstr.s );
> >>> + }
> >>> +}
> >>> +
> >>> +int
> >>> +main()
> >>> +{
> >>> + test01();
> >>> + test02();
> >>> + test03();
> >>> + test04();
> >>> +}
> >>> diff --git
> a/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/wchar_t/string_view.cc
> b/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/wchar_t/string_view.cc
> >>> new file mode 100644
> >>> index 00000000000..cfb73c4c510
> >>> --- /dev/null
> >>> +++
> b/libstdc++-v3/testsuite/27_io/basic_stringstream/cons/wchar_t/string_view.cc
> >>> @@ -0,0 +1,3 @@
> >>> +#define C wchar_t
> >>> +#define L(a) L##a
> >>> +#include "../char/string_view.cc"
> >>> --
> >>> 2.49.0
> >>>
> >>
> >
> >
>
>
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