On Wed, Apr 23, 2025 at 2:03 PM Tomasz Kamiński <[email protected]> wrote:
> When width parameter is specified for formatting range, tuple or escaped
> presentation of string, we used to format characters to temporary string,
> and write produce sequence padded according to the spec. However, once the
> estimated width of formatted representation of input is larger than the
> value
> of spec width, it can be written directly to the output. This limits size
> of
> required allocation, especially for large ranges.
>
> Similarly, if precision (maximum) width is provided for string
> presentation,
> on a prefix of sequence with estimated width not greater than precision,
> needs
> to be buffered.
>
> To realize above, this commit implements a new _Padding_sink
> specialization.
> This sink holds an output iterator, a value of padding width, (optionally)
> maximum width and a string buffer inherited from _Str_sink.
> Then any incoming characters are treated in one of following ways,
> depending of
> estimated width W of written sequence:
> * written to string if W is smaller than padding width and maximum width
> (if present)
> * ignored, if W is greater than maximum width
> * written to output iterator, if W is greater than padding width
>
> The padding sink is used instead of _Str_sink in __format::__format_padded,
> __formatter_str::_M_format_escaped functions.
>
> Furthermore __formatter_str::_M_format implementation was reworked, to:
> * reduce number of instantiations by delegating to _Rg& and const _Rg&
> overloads,
> * non-debug presentation is written to _Out directly or via _Padding_sink
> * if maximum width is specified for debug format with non-unicode encoding,
> string size is limited to that number.
>
> PR libstdc++/109162
>
> libstdc++-v3/ChangeLog:
>
> * include/bits/formatfwd.h (__simply_formattable_range): Moved from
> std/format.
> * include/std/format (__formatter_str::_format): Extracted escaped
> string handling to separate method...
> (__formatter_str::_M_format_escaped): Use __Padding_sink.
> (__formatter_str::_M_format): Adjusted implementation.
> (__formatter_str::_S_trunc): Extracted as namespace function...
> (__format::_truncate): Extracted from __formatter_str::_S_trunc.
> (__format::_Seq_sink): Removed forward declarations, made members
> protected and non-final.
> (_Seq_sink::_M_trim): Define.
> (_Seq_sink::_M_span): Renamed from view.
> (_Seq_sink::view): Returns string_view instead of span.
> (__format::_Str_sink): Moved after _Seq_sink.
> (__format::__format_padded): Use _Padding_sink.
> * testsuite/std/format/debug.cc: Add timeout and new tests.
> * testsuite/std/format/ranges/sequence.cc: Specify unicode as
> encoding and new tests.
> * testsuite/std/format/ranges/string.cc: Likewise.
> * testsuite/std/format/tuple.cc: Likewise.
> ---
> This is for sure 16 material, and nothing to backport.
> This addressed the TODO I created in __format_padded.
> OK for trunk after 15.1?
>
> libstdc++-v3/include/bits/formatfwd.h | 8 +
> libstdc++-v3/include/std/format | 396 +++++++++++++-----
> libstdc++-v3/testsuite/std/format/debug.cc | 386 ++++++++++++++++-
> .../testsuite/std/format/ranges/sequence.cc | 116 +++++
> .../testsuite/std/format/ranges/string.cc | 63 +++
> libstdc++-v3/testsuite/std/format/tuple.cc | 93 ++++
> 6 files changed, 957 insertions(+), 105 deletions(-)
>
> diff --git a/libstdc++-v3/include/bits/formatfwd.h
> b/libstdc++-v3/include/bits/formatfwd.h
> index 9ba658b078a..2d54ee5d30b 100644
> --- a/libstdc++-v3/include/bits/formatfwd.h
> +++ b/libstdc++-v3/include/bits/formatfwd.h
> @@ -131,6 +131,14 @@ namespace __format
> = ranges::input_range<const _Rg>
> && formattable<ranges::range_reference_t<const _Rg>, _CharT>;
>
> + // _Rg& and const _Rg& are both formattable and use same formatter
> + // specialization for their references.
> + template<typename _Rg, typename _CharT>
> + concept __simply_formattable_range
> + = __const_formattable_range<_Rg, _CharT>
> + && same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
> + remove_cvref_t<ranges::range_reference_t<const _Rg>>>;
> +
> template<typename _Rg, typename _CharT>
> using __maybe_const_range
> = __conditional_t<__const_formattable_range<_Rg, _CharT>, const
> _Rg, _Rg>;
> diff --git a/libstdc++-v3/include/std/format
> b/libstdc++-v3/include/std/format
> index 7d3067098be..355db5f2a60 100644
> --- a/libstdc++-v3/include/std/format
> +++ b/libstdc++-v3/include/std/format
> @@ -56,7 +56,7 @@
> #include <bits/ranges_base.h> // input_range, range_reference_t
> #include <bits/ranges_util.h> // subrange
> #include <bits/ranges_algobase.h> // ranges::copy
> -#include <bits/stl_iterator.h> // back_insert_iterator
> +#include <bits/stl_iterator.h> // back_insert_iterator, counted_iterator
> #include <bits/stl_pair.h> // __is_pair
> #include <bits/unicode.h> // __is_scalar_value, _Utf_view, etc.
> #include <bits/utility.h> // tuple_size_v
> @@ -99,19 +99,12 @@ namespace __format
>
> // Size for stack located buffer
> template<typename _CharT>
> - constexpr size_t __stackbuf_size = 32 * sizeof(void*) / sizeof(_CharT);
> + constexpr size_t __stackbuf_size = 32 * sizeof(void*) /
> sizeof(_CharT);
>
> // Type-erased character sinks.
> template<typename _CharT> class _Sink;
> template<typename _CharT> class _Fixedbuf_sink;
> - template<typename _Seq> class _Seq_sink;
> -
> - template<typename _CharT, typename _Alloc = allocator<_CharT>>
> - using _Str_sink
> - = _Seq_sink<basic_string<_CharT, char_traits<_CharT>, _Alloc>>;
> -
> - // template<typename _CharT, typename _Alloc = allocator<_CharT>>
> - // using _Vec_sink = _Seq_sink<vector<_CharT, _Alloc>>;
> + template<typename _Out, typename _CharT> class _Padding_sink;
>
> // Output iterator that writes to a type-erase character sink.
> template<typename _CharT>
> @@ -892,6 +885,25 @@ namespace __format
> __spec._M_fill);
> }
>
> + template<typename _CharT>
> + size_t
> + __truncate(basic_string_view<_CharT>& __s, size_t __prec)
> + {
> + if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
> + {
> + if (__prec != (size_t)-1)
> + return __unicode::__truncate(__s, __prec);
> + else
> + return __unicode::__field_width(__s);
> + }
> + else
> + {
> + __s = __s.substr(0, __prec);
> + return __s.size();
> + }
> + }
> +
> +
> // Values are indices into _Escapes::all.
> enum class _Term_char : unsigned char {
> _Tc_quote = 12,
> @@ -1327,82 +1339,110 @@ namespace __format
> format(basic_string_view<_CharT> __s,
> basic_format_context<_Out, _CharT>& __fc) const
> {
> - constexpr auto __term = __format::_Term_char::_Tc_quote;
> - const auto __write_direct = [&]
> - {
> - if (_M_spec._M_type == _Pres_esc)
> - return __format::__write_escaped(__fc.out(), __s, __term);
> - else
> - return __format::__write(__fc.out(), __s);
> - };
> + if (_M_spec._M_type == _Pres_esc)
> + return _M_format_escaped(__s, __fc);
>
> if (_M_spec._M_width_kind == _WP_none
> && _M_spec._M_prec_kind == _WP_none)
> - return __write_direct();
> + return __format::__write(__fc.out(), __s);
>
> - const size_t __prec =
> - _M_spec._M_prec_kind != _WP_none
> - ? _M_spec._M_get_precision(__fc)
> - : basic_string_view<_CharT>::npos;
> + const size_t __maxwidth = _M_spec._M_get_precision(__fc);
> + const size_t __width = __format::__truncate(__s, __maxwidth);
> + return __format::__write_padded_as_spec(__s, __width, __fc,
> _M_spec);
> + }
>
> - const size_t __estimated_width = _S_trunc(__s, __prec);
> - // N.B. Escaping only increases width
> - if (_M_spec._M_get_width(__fc) <= __estimated_width
> - && _M_spec._M_prec_kind == _WP_none)
> - return __write_direct();
> + template<typename _Out>
> + _Out
> + _M_format_escaped(basic_string_view<_CharT> __s,
> + basic_format_context<_Out, _CharT>& __fc) const
> + {
> + constexpr auto __term = __format::_Term_char::_Tc_quote;
> + const size_t __padwidth = _M_spec._M_get_width(__fc);
> + if (__padwidth == 0 && _M_spec._M_prec_kind == _WP_none)
> + return __format::__write_escaped(__fc.out(), __s, __term);
>
> - if (_M_spec._M_type != _Pres_esc)
> - return __format::__write_padded_as_spec(__s, __estimated_width,
> - __fc, _M_spec);
> + const size_t __maxwidth = _M_spec._M_get_precision(__fc);
> + const size_t __width = __truncate(__s, __maxwidth);
> + // N.B. Escaping only increases width
> + if (__padwidth <= __width && _M_spec._M_prec_kind == _WP_none)
> + return __format::__write_escaped(__fc.out(), __s, __term);
>
> - __format::_Str_sink<_CharT> __sink;
> - __format::__write_escaped(__sink.out(), __s, __term);
> - basic_string_view<_CharT> __escaped(__sink.view().data(),
> - __sink.view().size());
> - const size_t __escaped_width = _S_trunc(__escaped, __prec);
> // N.B. [tab:format.type.string] defines '?' as
> // Copies the escaped string ([format.string.escaped]) to the
> output,
> // so precision seem to appy to escaped string.
> - return __format::__write_padded_as_spec(__escaped,
> __escaped_width,
> - __fc, _M_spec);
> + _Padding_sink<_Out, _CharT> __sink(__fc.out(), __padwidth,
> __maxwidth);
> + __format::__write_escaped(__sink.out(), __s, __term);
> + return __sink._M_finish(_M_spec._M_align, _M_spec._M_fill);
> }
>
> #if __glibcxx_format_ranges // C++ >= 23 && HOSTED
> template<ranges::input_range _Rg, typename _Out>
> requires same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
> _CharT>
> - typename basic_format_context<_Out, _CharT>::iterator
> + _Out
> _M_format_range(_Rg&& __rg, basic_format_context<_Out, _CharT>&
> __fc) const
> {
> + using _Range = remove_reference_t<_Rg>;
> using _String = basic_string<_CharT>;
> using _String_view = basic_string_view<_CharT>;
> - if constexpr (ranges::forward_range<_Rg> ||
> ranges::sized_range<_Rg>)
> + if constexpr (!is_lvalue_reference_v<_Rg>)
> + return _M_format_range<_Range&>(__rg, __fc);
> + else if constexpr (!is_const_v<_Range>
> + && __simply_formattable_range<_Range,
> _CharT>)
> + return _M_format_range<const _Range&>(__rg, __fc);
> + else if constexpr (ranges::contiguous_range<_Rg>)
> + {
> + _String_view __str(ranges::data(__rg),
> + size_t(ranges::distance(__rg)));
> + return format(__str, __fc);
> + }
> + else if (_M_spec._M_type != _Pres_esc)
> + {
> + const size_t __padwidth = _M_spec._M_get_width(__fc);
> + if (__padwidth == 0 && _M_spec._M_prec_kind == _WP_none)
> + return ranges::copy(__rg, __fc.out()).out;
> +
> + _Padding_sink<_Out, _CharT> __sink(__fc.out(), __padwidth,
> +
> _M_spec._M_get_precision(__fc));
> + ranges::copy(__rg, __sink.out());
> + return __sink._M_finish(_M_spec._M_align, _M_spec._M_fill);
> + }
> + else if constexpr (ranges::forward_range<_Rg> ||
> ranges::sized_range<_Rg>)
> {
> const size_t __n(ranges::distance(__rg));
> - if constexpr (ranges::contiguous_range<_Rg>)
> - return format(_String_view(ranges::data(__rg), __n), __fc);
> - else if (__n <= __format::__stackbuf_size<_CharT>)
> + size_t __w = __n;
> + if constexpr
> (!__unicode::__literal_encoding_is_unicode<_CharT>())
> + if (size_t __max = _M_spec._M_get_precision(__fc); __n >
> __max)
> + __w == __max;
> +
> + if (__w <= __format::__stackbuf_size<_CharT>)
> {
> _CharT __buf[__format::__stackbuf_size<_CharT>];
> - ranges::copy(__rg, __buf);
> - return format(_String_view(__buf, __n), __fc);
> + ranges::copy_n(ranges::begin(__rg), __w, __buf);
> + return _M_format_escaped(_String_view(__buf, __n), __fc);
> }
> - else if constexpr (ranges::sized_range<_Rg>)
> - return format(_String(from_range, __rg), __fc);
> else if constexpr (ranges::random_access_range<_Rg>)
> {
> ranges::iterator_t<_Rg> __first = ranges::begin(__rg);
> - ranges::subrange __sub(__first, __first + __n);
> - return format(_String(from_range, __sub), __fc);
> + ranges::subrange __sub(__first, __first + __w);
> + return _M_format_escaped(_String(from_range, __sub),
> __fc);
> }
> + else if (__w <= __n)
> + {
> + ranges::subrange
> __sub(counted_iterator(ranges::begin(__rg)),
> + default_sentinel);
>
Local change that I forgot to commit, before sending:
+ ranges::subrange __sub(
+ counted_iterator(ranges::begin(__rg), __w),
+ default_sentinel);
+ return _M_format_escaped(_String(from_range, __sub),
> __fc);
>
+ }
> + else if constexpr (ranges::sized_range<_Rg>)
> + return _M_format_escaped(_String(from_range, __rg), __fc);
> else
> {
> // N.B. preserve the computed size
> ranges::subrange __sub(__rg, __n);
> - return format(_String(from_range, __sub), __fc);
> + return _M_format_escaped(_String(from_range, __sub),
> __fc);
> }
> }
> else
> - return format(_String(from_range, __rg), __fc);
> + return _M_format_escaped(_String(from_range, __rg), __fc);
> }
>
> constexpr void
> @@ -1411,23 +1451,6 @@ namespace __format
> #endif
>
> private:
> - static size_t
> - _S_trunc(basic_string_view<_CharT>& __s, size_t __prec)
> - {
> - if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
> - {
> - if (__prec != basic_string_view<_CharT>::npos)
> - return __unicode::__truncate(__s, __prec);
> - else
> - return __unicode::__field_width(__s);
> - }
> - else
> - {
> - __s = __s.substr(0, __prec);
> - return __s.size();
> - }
> - }
> -
> _Spec<_CharT> _M_spec{};
> };
>
> @@ -3271,12 +3294,12 @@ namespace __format
> // A sink that fills a sequence (e.g. std::string, std::vector,
> std::deque).
> // Writes to a buffer then appends that to the sequence when it fills
> up.
> template<typename _Seq>
> - class _Seq_sink final : public _Buf_sink<typename _Seq::value_type>
> + class _Seq_sink : public _Buf_sink<typename _Seq::value_type>
> {
> using _CharT = typename _Seq::value_type;
>
> _Seq _M_seq;
> -
> + protected:
> // Transfer buffer contents to the sequence, so buffer can be
> refilled.
> void
> _M_overflow() override
> @@ -3348,6 +3371,17 @@ namespace __format
> }
> }
>
> + void _M_trim(span<const _CharT> __s)
> + requires __is_specialization_of<_Seq, basic_string>
> + {
> + _GLIBCXX_DEBUG_ASSERT(__s.data() == this->_M_buf
> + || __s.data() == _M_seq.data());
> + if (__s.data() == _M_seq.data())
> + _M_seq.resize(__s.size());
> + else
> + this->_M_reset(this->_M_buf, __s.size());
> + }
> +
> public:
> // TODO: for SSO string, use SSO buffer as initial span, then switch
> // to _M_buf if it overflows? Or even do that for all unused
> capacity?
> @@ -3373,7 +3407,7 @@ namespace __format
> // A writable span that views everything written to the sink.
> // Will be either a view over _M_seq or the used part of _M_buf.
> span<_CharT>
> - view()
> + _M_span()
> {
> auto __s = this->_M_used();
> if (_M_seq.size())
> @@ -3384,9 +3418,21 @@ namespace __format
> }
> return __s;
> }
> +
> + basic_string_view<_CharT>
> + view()
> + {
> + auto __span = _M_span();
> + return basic_string_view<_CharT>(__span.data(), __span.size());
> + }
> };
>
> - // A sink that writes to an output iterator.
> + template<typename _CharT, typename _Alloc = allocator<_CharT>>
> + using _Str_sink
> + = _Seq_sink<basic_string<_CharT, char_traits<_CharT>, _Alloc>>;
> +
> + // template<typename _CharT, typename _Alloc = allocator<_CharT>>
> + // using _Vec_sink = _Seq_sink<vector<_CharTthis-> sink that writes to
> an output iterator.
> // Writes to a fixed-size buffer and then flushes to the output iterator
> // when the buffer fills up.
> template<typename _CharT, typename _OutIter>
> @@ -3554,6 +3600,171 @@ namespace __format
> }
> };
>
> + // A sink for handling the padded outputs (_M_padwidth) or truncated
> + // (_M_maxwidth). The handling is done by writting to buffer
> (_Str_strink)
> + // until sufficient number of characters is written. After that if
> sequence
> + // is longer than _M_padwidth it's written to _M_out, and further
> writes are
> + // either:
> + // * buffered and forwarded to _M_out, if below _M_maxwidth,
> + // * ignored otherwise
> + // If field width of written sequence is no greater than _M_padwidth,
> the
> + // sequence is written during _M_finish call.
> + template<typename _Out, typename _CharT>
> + class _Padding_sink : public _Str_sink<_CharT>
> + {
> + const size_t _M_padwidth;
> + const size_t _M_maxwidth;
> + _Out _M_out;
> + size_t _M_printwidth;
> +
> + [[__gnu__::__always_inline__]]
> + bool
> + _M_ignoring() const
> + {
> + return _M_printwidth >= _M_maxwidth;
> + }
> +
> + [[__gnu__::__always_inline__]]
> + bool
> + _M_buffering() const
> + {
> + if (_M_printwidth < _M_padwidth)
> + return true;
> + if (_M_maxwidth != (size_t)-1)
> + return _M_printwidth < _M_maxwidth;
> + return false;
> + }
> +
> + void
> + _M_flush()
> + {
> + span<_CharT> __new = this->_M_used();
> + basic_string_view<_CharT> __str(__new.data(), __new.size());
> + _M_out = __format::__write(std::move(_M_out), __str);
> + this->_M_rewind();
> + }
> +
> + bool
> + _M_force_update()
> + {
> + auto __str = this->view();
> + // Compute actual field width, possibly truncated.
> + _M_printwidth = __format::__truncate(__str, _M_maxwidth);
> + if (_M_ignoring())
> + this->_M_trim(__str);
> + if (_M_buffering())
> + return true;
> +
> + // We have more characters than padidng, no padding is needed,
> + // write direclty to _M_out.
> + if (_M_printwidth >= _M_padwidth)
> + _M_out = __format::__write(std::move(_M_out), __str);
> + // We reached _M_maxwidth that is smaller than _M_padwidth.
> + // Store the prefix sequence in _M_seq, and free _M_buf.
> + else
> + _Str_sink<_CharT>::_M_overflow();
> +
> + // Use internal buffer for writes to _M_out.
> + this->_M_reset(this->_M_buf);
> + return false;
> + }
> +
> + bool
> + _M_update(size_t __new)
> + {
> + _M_printwidth += __new;
> + if (_M_buffering())
> + return true;
> + return _M_force_update();
> + }
> +
> + void
> + _M_overflow() override
> + {
> + // Ignore characters in buffer, and override it.
> + if (_M_ignoring())
> + this->_M_rewind();
> + // Write buffer to _M_out, and override it.
> + else if (!_M_buffering())
> + _M_flush();
> + // Update written count, and if input still should be buffered,
> + // flush the to _M_seq.
> + else if (_M_update(this->_M_used().size()))
> + _Str_sink<_CharT>::_M_overflow();
> + }
> +
> + typename _Sink<_CharT>::_Reservation
> + _M_reserve(size_t __n) override
> + {
> + // Ignore characters in buffer, if any.
> + if (_M_ignoring())
> + this->_M_rewind();
> + else if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
> + if (!_M_buffering())
> + {
> + // Write pending characters if any
> + if (!this->_M_used().empty())
> + _M_flush();
> + // Try to reserve from _M_out sink.
> + if (auto __reserved = _M_out._M_reserve(__n))
> + return __reserved;
> + }
> + return _Sink<_CharT>::_M_reserve(__n);
> + }
> +
> + void
> + _M_bump(size_t __n) override
> + {
> + // Ignore the written characters.
> + if (_M_ignoring())
> + return;
> + // If reservation was made directy sink associated _M_out,
> + // _M_bump will be called on that sink.
> + _Sink<_CharT>::_M_bump(__n);
> + if (_M_buffering())
> + _M_update(__n);
> + }
> +
> + public:
> + [[__gnu__::__always_inline__]]
> + explicit _Padding_sink(_Out __out, size_t __padwidth)
> + : _M_padwidth(__padwidth), _M_maxwidth(-1),
> + _M_out(std::move(__out)), _M_printwidth(0)
> + { }
> +
> + [[__gnu__::__always_inline__]]
> + explicit _Padding_sink(_Out __out, size_t __padwidth, size_t
> __maxwidth)
> + : _M_padwidth(__padwidth), _M_maxwidth(__maxwidth),
> + _M_out(std::move(__out)), _M_printwidth(0)
> + { }
> +
> + _Out
> + _M_finish(_Align __align, char32_t __fill_char)
> + {
> + // Handle any characters in the buffer.
> + if (auto __rem = this->_M_used().size())
> + if (_M_ignoring())
> + this->_M_rewind();
> + else if (!_M_buffering())
> + _M_flush();
> + else
> + _M_update(__rem);
> +
> + if (!_M_buffering() || !_M_force_update())
> + // Characters were already written to _M_out.
> + if (_M_printwidth >= _M_padwidth)
> + return std::move(_M_out);
> +
> + const auto __str = this->view();
> + if (_M_printwidth >= _M_padwidth)
> + return __format::__write(std::move(_M_out), __str);
> +
> + const size_t __nfill = _M_padwidth - _M_printwidth;
> + return __format::__write_padded(std::move(_M_out), __str,
> + __align, __nfill, __fill_char);
> + }
> + };
> +
> enum _Arg_t : unsigned char {
> _Arg_none, _Arg_bool, _Arg_c, _Arg_i, _Arg_u, _Arg_ll, _Arg_ull,
> _Arg_flt, _Arg_dbl, _Arg_ldbl, _Arg_str, _Arg_sv, _Arg_ptr,
> _Arg_handle,
> @@ -5160,7 +5371,8 @@ namespace __format
> // as we need to format to temporary buffer, using the same
> iterator.
> static_assert(is_same_v<_Out, __format::_Sink_iter<_CharT>>);
>
> - if (__spec._M_get_width(__fc) == 0)
> + const size_t __padwidth = __spec._M_get_width(__fc);
> + if (__padwidth == 0)
> return __call(__fc);
>
> struct _Restore_out
> @@ -5169,48 +5381,30 @@ namespace __format
> : _M_ctx(std::addressof(__fc)), _M_out(__fc.out())
> { }
>
> - void _M_trigger()
> + void
> + _M_disarm()
> + { _M_ctx = nullptr; }
> +
> + ~_Restore_out()
> {
> if (_M_ctx)
> _M_ctx->advance_to(_M_out);
> - _M_ctx = nullptr;
> }
>
> - ~_Restore_out()
> - { _M_trigger(); }
> -
> private:
> basic_format_context<_Sink_iter<_CharT>, _CharT>* _M_ctx;
> _Sink_iter<_CharT> _M_out;
> };
>
> _Restore_out __restore(__fc);
> - // TODO Consider double sinking, first buffer of width
> - // size and then original sink, if first buffer is overun
> - // we do not need to align
> - _Str_sink<_CharT> __buf;
> - __fc.advance_to(__buf.out());
> + _Padding_sink<_Sink_iter<_CharT>, _CharT> __sink(__fc.out(),
> __padwidth);
> + __fc.advance_to(__sink.out());
> __call(__fc);
> - __restore._M_trigger();
> -
> - basic_string_view<_CharT> __str(__buf.view());
> - size_t __width;
> - if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
> - __width = __unicode::__field_width(__str);
> - else
> - __width = __str.size();
> -
> - return __format::__write_padded_as_spec(__str, __width, __fc,
> __spec);
> + __fc.advance_to(__sink._M_finish(__spec._M_align, __spec._M_fill));
> + __restore._M_disarm();
> + return __fc.out();
> }
>
> - // _Rg& and const _Rg& are both formattable and use same formatter
> - // specialization for their references.
> - template<typename _Rg, typename _CharT>
> - concept __simply_formattable_range
> - = __const_formattable_range<_Rg, _CharT>
> - && same_as<remove_cvref_t<ranges::range_reference_t<_Rg>>,
> - remove_cvref_t<ranges::range_reference_t<const _Rg>>>;
> -
> template<size_t _Pos, typename _Tp, typename _CharT>
> struct __indexed_formatter_storage
> {
> diff --git a/libstdc++-v3/testsuite/std/format/debug.cc
> b/libstdc++-v3/testsuite/std/format/debug.cc
> index 71bb7f4a0fe..d3b025eabb4 100644
> --- a/libstdc++-v3/testsuite/std/format/debug.cc
> +++ b/libstdc++-v3/testsuite/std/format/debug.cc
> @@ -2,6 +2,7 @@
> // { dg-options "-fexec-charset=UTF-8 -fwide-exec-charset=UTF-32BE
> -DUNICODE_ENC" { target be } }
> // { dg-do run { target c++23 } }
> // { dg-add-options no_pch }
> +// { dg-timeout-factor 2 }
>
> #include <format>
> #include <testsuite_hooks.h>
> @@ -114,11 +115,11 @@ test_extended_ascii()
> }
> }
>
> -#if UNICODE_ENC
> template<typename _CharT>
> void
> test_unicode_escapes()
> {
> +#if UNICODE_ENC
> std::basic_string<_CharT> res;
>
> const auto in = WIDEN(
> @@ -160,12 +161,14 @@ test_unicode_escapes()
> res = fdebug(in[5]);
> VERIFY( res == WIDEN("'\U0001f984'") );
> }
> +#endif // UNICODE_ENC
> }
>
> template<typename _CharT>
> void
> test_grapheme_extend()
> {
> +#if UNICODE_ENC
> std::basic_string<_CharT> res;
>
> const auto vin = WIDEN("o\u0302\u0323");
> @@ -184,12 +187,14 @@ test_grapheme_extend()
> res = fdebug(in[1]);
> VERIFY( res == WIDEN(R"('\u{302}')") );
> }
> +#endif // UNICODE_ENC
> }
>
> template<typename _CharT>
> void
> test_replacement_char()
> {
> +#if UNICODE_ENC
> std::basic_string<_CharT> repl = WIDEN("\uFFFD");
> std::basic_string<_CharT> res = fdebug(repl);
> VERIFY( res == WIDEN("\"\uFFFD\"") );
> @@ -197,11 +202,13 @@ test_replacement_char()
> repl = WIDEN("\uFFFD\uFFFD");
> res = fdebug(repl);
> VERIFY( res == WIDEN("\"\uFFFD\uFFFD\"") );
> +#endif // UNICODE_ENC
> }
>
> void
> test_ill_formed_utf8_seq()
> {
> +#if UNICODE_ENC
> std::string_view seq = "\xf0\x9f\xa6\x84"; // \U0001F984
> std::string res;
>
> @@ -233,11 +240,13 @@ test_ill_formed_utf8_seq()
> VERIFY( res == R"('\x{84}')" );
> res = fdebug(seq.substr(3, 1));
> VERIFY( res == R"("\x{84}")" );
> +#endif // UNICODE_ENC
> }
>
> void
> test_ill_formed_utf32()
> {
> +#if UNICODE_ENC
> std::wstring res;
>
> wchar_t ic1 = static_cast<wchar_t>(0xff'ffff);
> @@ -255,8 +264,8 @@ test_ill_formed_utf32()
> std::wstring is2(1, ic2);
> res = fdebug(is2);
> VERIFY( res == LR"("\x{ffffffff}")" );
> -}
> #endif // UNICODE_ENC
> +}
>
> template<typename _CharT>
> void
> @@ -331,6 +340,375 @@ test_prec()
> #endif // UNICODE_ENC
> }
>
> +bool strip_quote(std::string_view& v)
> +{
> + if (!v.starts_with('"'))
> + return false;
> + v.remove_prefix(1);
> + return true;
> +}
> +
> +bool strip_quotes(std::string_view& v)
> +{
> + if (!v.starts_with('"') || !v.ends_with('"'))
> + return false;
> + v.remove_prefix(1);
> + v.remove_suffix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, size_t n, char c)
> +{
> + size_t pos = v.find_first_not_of(c);
> + if (pos == std::string_view::npos)
> + pos = v.size();
> + if (pos != n)
> + return false;
> + v.remove_prefix(n);
> + return true;
> +}
> +
> +void test_padding()
> +{
> + std::string res;
> + std::string_view resv;
> +
> + // width and size are 26
> + std::string in = "abcdefghijklmnopqrstuvwxyz";
> + in += in; // width and size are 52
> + in += in; // width and size are 104
> + in += in; // width and size are 208
> + in += in; // width and size are 416
> + std::string_view inv = in;
> +
> + resv = res = std::format("{}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.500}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.400}", in);
> + VERIFY( resv == inv.substr(0, 400) );
> +
> + resv = res = std::format("{:.200}", in);
> + VERIFY( resv == inv.substr(0, 200) );
> +
> + resv = res = std::format("{:.10}", in);
> + VERIFY( resv == inv.substr(0, 10) );
> +
> + resv = res = std::format("{:.0}", in);
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>20}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>20.500}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>20.400}", in);
> + VERIFY( resv == inv.substr(0, 400) );
> +
> + resv = res = std::format("{:*>20.200}", in);
> + VERIFY( resv == inv.substr(0, 200) );
> +
> + resv = res = std::format("{:*>20.10}", in);
> + VERIFY( strip_prefix(resv, 10, '*') );
> + VERIFY( resv == inv.substr(0, 10) );
> +
> + resv = res = std::format("{:*>20.0}", in);
> + VERIFY( strip_prefix(resv, 20, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>450}", in);
> + VERIFY( strip_prefix(resv, 34, '*') );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.500}", in);
> + VERIFY( strip_prefix(resv, 34, '*') );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.420}", in);
> + VERIFY( strip_prefix(resv, 34, '*') );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.400}", in);
> + VERIFY( strip_prefix(resv, 50, '*') );
> + VERIFY( resv == inv.substr(0, 400) );
> +
> + resv = res = std::format("{:*>450.200}", in);
> + VERIFY( strip_prefix(resv, 250, '*') );
> + VERIFY( resv == inv.substr(0, 200) );
> +
> + resv = res = std::format("{:*>450.10}", in);
> + VERIFY( strip_prefix(resv, 440, '*') );
> + VERIFY( resv == inv.substr(0, 10) );
> +
> + resv = res = std::format("{:*>450.0}", in);
> + VERIFY( strip_prefix(resv, 450, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.500?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.400?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 399) );
> +
> + resv = res = std::format("{:.200?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 199) );
> +
> + resv = res = std::format("{:.10?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 9) );
> +
> + resv = res = std::format("{:.1?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:.0?}", in);
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>20?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>20.500?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>20.400?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 399) );
> +
> + resv = res = std::format("{:*>20.200?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 199) );
> +
> + resv = res = std::format("{:*>20.10?}", in);
> + VERIFY( strip_prefix(resv, 10, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 9) );
> +
> + resv = res = std::format("{:*>20.1?}", in);
> + VERIFY( strip_prefix(resv, 19, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>20.0?}", in);
> + VERIFY( strip_prefix(resv, 20, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>450?}", in);
> + VERIFY( strip_prefix(resv, 32, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.500?}", in);
> + VERIFY( strip_prefix(resv, 32, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.420?}", in);
> + VERIFY( strip_prefix(resv, 32, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>450.400?}", in);
> + VERIFY( strip_prefix(resv, 50, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 399) );
> +
> + resv = res = std::format("{:*>450.200?}", in);
> + VERIFY( strip_prefix(resv, 250, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 199) );
> +
> + resv = res = std::format("{:*>450.10?}", in);
> + VERIFY( strip_prefix(resv, 440, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 9) );
> +
> + resv = res = std::format("{:*>450.1?}", in);
> + VERIFY( strip_prefix(resv, 449, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>450.0?}", in);
> + VERIFY( strip_prefix(resv, 450, '*') );
> + VERIFY( resv == "" );
> +
> +#if UNICODE_ENC
> + // width is 3, size is 15
> + in = "o\u0302\u0323i\u0302\u0323u\u0302\u0323";
> + in += in; // width is 6, size is 30
> + in += in; // width is 12, size is 60
> + in += in; // width is 24, size is 120
> + in += in; // width is 48, size is 240
> + in += in; // width is 96, size is 480
> + in += in; // width is 192, size is 960
> + inv = in;
> +
> + resv = res = std::format("{:}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.200}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.96}", in);
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:.12}", in);
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:.3}", in);
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:.0}", in);
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>10}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>10.200}", in);
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>10.96}", in);
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:*>10.12}", in);
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:*>10.3}", in);
> + VERIFY( strip_prefix(resv, 7, '*') );
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:*>10.0}", in);
> + VERIFY( strip_prefix(resv, 10, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>240s}", in);
> + VERIFY( strip_prefix(resv, 48, '*') );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>240.200s}", in);
> + VERIFY( strip_prefix(resv, 48, '*') );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>240.96s}", in);
> + VERIFY( strip_prefix(resv, 144, '*') );
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:*>240.12}", in);
> + VERIFY( strip_prefix(resv, 228, '*') );
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:*>240.3s}", in);
> + VERIFY( strip_prefix(resv, 237, '*') );
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:*>240.0s}", in);
> + VERIFY( strip_prefix(resv, 240, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.200?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:.97?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:.13?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:.4?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:.1?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:.0?}", in);
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>10?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>10.200?}", in);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>10.97?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:*>10.13?}", in);
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:*>10.4?}", in);
> + VERIFY( strip_prefix(resv, 6, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:*>10.1?}", in);
> + VERIFY( strip_prefix(resv, 9, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>10.0?}", in);
> + VERIFY( strip_prefix(resv, 10, '*') );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>240?}", in);
> + VERIFY( strip_prefix(resv, 46, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>240.200?}", in);
> + VERIFY( strip_prefix(resv, 46, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == inv );
> +
> + resv = res = std::format("{:*>240.97?}", in);
> + VERIFY( strip_prefix(resv, 143, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 480) );
> +
> + resv = res = std::format("{:*>240.13?}", in);
> + VERIFY( strip_prefix(resv, 227, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 60) );
> +
> + resv = res = std::format("{:*>240.4?}", in);
> + VERIFY( strip_prefix(resv, 236, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == inv.substr(0, 15) );
> +
> + resv = res = std::format("{:*>240.1?}", in);
> + VERIFY( strip_prefix(resv, 239, '*') );
> + VERIFY( strip_quote(resv) );
> + VERIFY( resv == "" );
> +
> + resv = res = std::format("{:*>240.0?}", in);
> + VERIFY( strip_prefix(resv, 240, '*') );
> + VERIFY( resv == "" );
> +#endif // UNICODE_ENC
> +}
> +
> void test_char_as_wchar()
> {
> std::wstring res;
> @@ -435,7 +813,6 @@ int main()
> test_extended_ascii<char>();
> test_extended_ascii<wchar_t>();
>
> -#if UNICODE_ENC
> test_unicode_escapes<char>();
> test_unicode_escapes<wchar_t>();
> test_grapheme_extend<char>();
> @@ -444,12 +821,13 @@ int main()
> test_replacement_char<wchar_t>();
> test_ill_formed_utf8_seq();
> test_ill_formed_utf32();
> -#endif // UNICODE_ENC
>
> test_fill<char>();
> test_fill<wchar_t>();
> test_prec<char>();
> test_prec<wchar_t>();
>
> + test_padding();
> +
> test_formatters_c();
> }
> diff --git a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> index f05f6ec1e1c..75fe4c19a52 100644
> --- a/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> +++ b/libstdc++-v3/testsuite/std/format/ranges/sequence.cc
> @@ -1,4 +1,5 @@
> // { dg-do run { target c++23 } }
> +// { dg-options "-fexec-charset=UTF-8" }
> // { dg-timeout-factor 2 }
>
> #include <array>
> @@ -6,6 +7,7 @@
> #include <list>
> #include <ranges>
> #include <span>
> +#include <string>
> #include <testsuite_hooks.h>
> #include <testsuite_iterators.h>
> #include <vector>
> @@ -199,9 +201,123 @@ test_nested()
> VERIFY( res == "+[01, 02, 11, 12]+" );
> }
>
> +bool strip_quote(std::string_view& v)
> +{
> + if (!v.starts_with('"'))
> + return false;
> + v.remove_prefix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, std::string_view expected, bool
> quoted = false)
> +{
> + if (quoted && !strip_quote(v))
> + return false;
> + if (!v.starts_with(expected))
> + return false;
> + v.remove_prefix(expected.size());
> + if (quoted && !strip_quote(v))
> + return false;
> + return true;
> +}
> +
> +bool strip_squares(std::string_view& v)
> +{
> + if (!v.starts_with('[') || !v.ends_with(']'))
> + return false;
> + v.remove_prefix(1);
> + v.remove_suffix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, size_t n, char c)
> +{
> + size_t pos = v.find_first_not_of(c);
> + if (pos == std::string_view::npos)
> + pos = v.size();
> + if (pos != n)
> + return false;
> + v.remove_prefix(n);
> + return true;
> +}
> +
> +void test_padding()
> +{
> + std::string res;
> + std::string_view resv;
> +
> + // width is 3, size is 15
> + std::string in = "o\u0302\u0323i\u0302\u0323u\u0302\u0323";
> + in += in; // width is 6, size is 30
> + in += in; // width is 12, size is 60
> + in += in; // width is 24, size is 120
> + in += in; // width is 48, size is 240
> + // width is 192, size is 960
> + std::vector<std::string> const vs{in, in, in, in};
> +
> + auto const check_elems = [=](std::string_view& v, bool quoted)
> + {
> + VERIFY( strip_prefix(v, in, quoted) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, quoted) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, quoted) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, quoted) );
> + return v.empty();
> + };
> +
> + resv = res = std::format("{}", vs);
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{:n}", vs);
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{::}", vs);
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, false) );
> +
> + resv = res = std::format("{:n:}", vs);
> + VERIFY( check_elems(resv, false) );
> +
> + resv = res = std::format("{:*>10}", vs);
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{:*>10n}", vs);
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{:*>10:}", vs);
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, false) );
> +
> + resv = res = std::format("{:*>10n:}", vs);
> + VERIFY( check_elems(resv, false) );
> +
> + resv = res = std::format("{:*>240}", vs);
> + VERIFY( strip_prefix(resv, 32, '*') );
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{:*>240n}", vs);
> + VERIFY( strip_prefix(resv, 34, '*') );
> + VERIFY( check_elems(resv, true) );
> +
> + resv = res = std::format("{:*>240:}", vs);
> + VERIFY( strip_prefix(resv, 40, '*') );
> + VERIFY( strip_squares(resv) );
> + VERIFY( check_elems(resv, false) );
> +
> + resv = res = std::format("{:*>240n:}", vs);
> + VERIFY( strip_prefix(resv, 42, '*') );
> + VERIFY( check_elems(resv, false) );
> +}
> +
> int main()
> {
> test_format_string();
> test_outputs();
> test_nested();
> + test_padding();
> }
> diff --git a/libstdc++-v3/testsuite/std/format/ranges/string.cc
> b/libstdc++-v3/testsuite/std/format/ranges/string.cc
> index cf39aa66e07..cebdd530168 100644
> --- a/libstdc++-v3/testsuite/std/format/ranges/string.cc
> +++ b/libstdc++-v3/testsuite/std/format/ranges/string.cc
> @@ -1,7 +1,9 @@
> // { dg-do run { target c++23 } }
> +// { dg-options "-fexec-charset=UTF-8" }
> // { dg-timeout-factor 2 }
>
> #include <format>
> +#include <forward_list>
> #include <span>
> #include <testsuite_hooks.h>
> #include <testsuite_iterators.h>
> @@ -218,6 +220,67 @@ test_nested()
> VERIFY( std::format("{::?s}", vv) == R"(["str1", "str2"])" );
> }
>
> +bool strip_quotes(std::string_view& v)
> +{
> + if (!v.starts_with('"') || !v.ends_with('"'))
> + return false;
> + v.remove_prefix(1);
> + v.remove_suffix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, size_t n, char c)
> +{
> + size_t pos = v.find_first_not_of(c);
> + if (pos == std::string_view::npos)
> + pos = v.size();
> + if (pos != n)
> + return false;
> + v.remove_prefix(n);
> + return true;
> +}
> +
> +
> +void test_padding()
> +{
> + std::string res;
> + std::string_view resv;
> +
> + // width is 3, size is 15
> + std::string in = "o\u0302\u0323i\u0302\u0323u\u0302\u0323";
> + in += in; // width is 6, size is 30
> + in += in; // width is 12, size is 60
> + in += in; // width is 24, size is 120
> + in += in; // width is 48, size is 240
> + in += in; // width is 96, size is 480
> + in += in; // width is 192, size is 960
> +
> + std::forward_list<char> lc(std::from_range, in);
> +
> + resv = res = std::format("{:s}", lc);
> + VERIFY( resv == in );
> +
> + resv = res = std::format("{:*>10s}", lc);
> + VERIFY( resv == in );
> +
> + resv = res = std::format("{:*>240s}", lc);
> + VERIFY( strip_prefix(resv, 48, '*') );
> + VERIFY( resv == in );
> +
> + resv = res = std::format("{:?s}", lc);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == in );
> +
> + resv = res = std::format("{:*>10?s}", lc);
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == in );
> +
> + resv = res = std::format("{:*>240?s}", lc);
> + VERIFY( strip_prefix(resv, 46, '*') );
> + VERIFY( strip_quotes(resv) );
> + VERIFY( resv == in );
> +}
> +
> int main()
> {
> test_format_string();
> diff --git a/libstdc++-v3/testsuite/std/format/tuple.cc
> b/libstdc++-v3/testsuite/std/format/tuple.cc
> index 62f9d293aab..ff0359b9aba 100644
> --- a/libstdc++-v3/testsuite/std/format/tuple.cc
> +++ b/libstdc++-v3/testsuite/std/format/tuple.cc
> @@ -1,4 +1,6 @@
> // { dg-do run { target c++23 } }
> +// { dg-options "-fexec-charset=UTF-8" }
> +// { dg-timeout-factor 2 }
>
> #include <format>
> #include <string>
> @@ -250,10 +252,101 @@ void test_nested()
> VERIFY( res == R"((): (1, "abc"))" );
> }
>
> +bool strip_quote(std::string_view& v)
> +{
> + if (!v.starts_with('"'))
> + return false;
> + v.remove_prefix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, std::string_view expected, bool
> quoted = false)
> +{
> + if (quoted && !strip_quote(v))
> + return false;
> + if (!v.starts_with(expected))
> + return false;
> + v.remove_prefix(expected.size());
> + if (quoted && !strip_quote(v))
> + return false;
> + return true;
> +}
> +
> +bool strip_parens(std::string_view& v)
> +{
> + if (!v.starts_with('(') || !v.ends_with(')'))
> + return false;
> + v.remove_prefix(1);
> + v.remove_suffix(1);
> + return true;
> +}
> +
> +bool strip_prefix(std::string_view& v, size_t n, char c)
> +{
> + size_t pos = v.find_first_not_of(c);
> + if (pos == std::string_view::npos)
> + pos = v.size();
> + if (pos != n)
> + return false;
> + v.remove_prefix(n);
> + return true;
> +}
> +
> +void test_padding()
> +{
> + std::string res;
> + std::string_view resv;
> +
> + // width is 3, size is 15
> + std::string in = "o\u0302\u0323i\u0302\u0323u\u0302\u0323";
> + in += in; // width is 6, size is 30
> + in += in; // width is 12, size is 60
> + in += in; // width is 24, size is 120
> + in += in; // width is 48, size is 240
> + // width is 192, size is 960
> + auto const ts = std::make_tuple(in, in, in, in);
> +
> + auto const check_elems = [=](std::string_view& v)
> + {
> + VERIFY( strip_prefix(v, in, true) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, true) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, true) );
> + VERIFY( strip_prefix(v, ", ", false) );
> + VERIFY( strip_prefix(v, in, true) );
> + return v.empty();
> + };
> +
> + resv = res = std::format("{}", ts);
> + VERIFY( strip_parens(resv) );
> + VERIFY( check_elems(resv) );
> +
> + resv = res = std::format("{:n}", ts);
> + VERIFY( check_elems(resv) );
> +
> + resv = res = std::format("{:*>10}", ts);
> + VERIFY( strip_parens(resv) );
> + VERIFY( check_elems(resv) );
> +
> + resv = res = std::format("{:*>10n}", ts);
> + VERIFY( check_elems(resv) );
> +
> + resv = res = std::format("{:*>240}", ts);
> + VERIFY( strip_prefix(resv, 32, '*') );
> + VERIFY( strip_parens(resv) );
> + VERIFY( check_elems(resv) );
> +
> + resv = res = std::format("{:*>240n}", ts);
> + VERIFY( strip_prefix(resv, 34, '*') );
> + VERIFY( check_elems(resv) );
> +}
> +
> int main()
> {
> test_format_string();
> test_outputs<char>();
> test_outputs<wchar_t>();
> test_nested();
> + test_padding();
> }
> --
> 2.49.0
>
>
