sl@0: // ----------------------------------------------------------------------------
sl@0: // internals.hpp : internal structs : stream_format_state, format_item.
sl@0: // included by format.hpp
sl@0: // ----------------------------------------------------------------------------
sl@0:
sl@0: // Copyright Samuel Krempp 2003. Use, modification, and distribution are
sl@0: // subject to the Boost Software License, Version 1.0. (See accompanying
sl@0: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
sl@0:
sl@0: // See http://www.boost.org/libs/format for library home page
sl@0:
sl@0: // ----------------------------------------------------------------------------
sl@0:
sl@0: #ifndef BOOST_FORMAT_INTERNALS_HPP
sl@0: #define BOOST_FORMAT_INTERNALS_HPP
sl@0:
sl@0:
sl@0: #include <string>
sl@0: #include <boost/assert.hpp>
sl@0: #include <boost/optional.hpp>
sl@0: #include <boost/limits.hpp>
sl@0: #include <boost/format/detail/compat_workarounds.hpp>
sl@0: #include <boost/format/alt_sstream.hpp> // used as a dummy stream
sl@0:
sl@0: namespace boost {
sl@0: namespace io {
sl@0: namespace detail {
sl@0:
sl@0:
sl@0: //---- stream_format_state --------------------------------------------------//
sl@0:
sl@0: // set of params that define the format state of a stream
sl@0: template<class Ch, class Tr>
sl@0: struct stream_format_state
sl@0: {
sl@0: typedef BOOST_IO_STD basic_ios<Ch, Tr> basic_ios;
sl@0:
sl@0: stream_format_state(Ch fill) { reset(fill); }
sl@0: // stream_format_state(const basic_ios& os) { set_by_stream(os); }
sl@0:
sl@0: void reset(Ch fill); //- sets to default state.
sl@0: void set_by_stream(const basic_ios& os); //- sets to os's state.
sl@0: void apply_on(basic_ios & os, //- applies format_state to the stream
sl@0: boost::io::detail::locale_t * loc_default = 0) const;
sl@0: template<class T>
sl@0: void apply_manip(T manipulator) //- modifies state by applying manipulator
sl@0: { apply_manip_body<Ch, Tr, T>( *this, manipulator) ; }
sl@0:
sl@0: // --- data ---
sl@0: std::streamsize width_;
sl@0: std::streamsize precision_;
sl@0: Ch fill_;
sl@0: std::ios_base::fmtflags flags_;
sl@0: std::ios_base::iostate rdstate_;
sl@0: std::ios_base::iostate exceptions_;
sl@0: boost::optional<boost::io::detail::locale_t> loc_;
sl@0: };
sl@0:
sl@0:
sl@0: //---- format_item ---------------------------------------------------------//
sl@0:
sl@0: // stores all parameters that can be specified in format strings
sl@0: template<class Ch, class Tr, class Alloc>
sl@0: struct format_item
sl@0: {
sl@0: enum pad_values { zeropad = 1, spacepad =2, centered=4, tabulation = 8 };
sl@0: // 1. if zeropad is set, all other bits are not,
sl@0: // 2. if tabulation is set, all others are not.
sl@0: // centered and spacepad can be mixed freely.
sl@0: enum arg_values { argN_no_posit = -1, // non-positional directive. will set argN later
sl@0: argN_tabulation = -2, // tabulation directive. (no argument read)
sl@0: argN_ignored = -3 // ignored directive. (no argument read)
sl@0: };
sl@0: typedef BOOST_IO_STD basic_ios<Ch, Tr> basic_ios;
sl@0: typedef detail::stream_format_state<Ch, Tr> stream_format_state;
sl@0: typedef ::std::basic_string<Ch, Tr, Alloc> string_type;
sl@0:
sl@0: format_item(Ch fill) :argN_(argN_no_posit), fmtstate_(fill),
sl@0: truncate_(max_streamsize()), pad_scheme_(0) {}
sl@0: void reset(Ch fill);
sl@0: void compute_states(); // sets states according to truncate and pad_scheme.
sl@0:
sl@0: static std::streamsize max_streamsize() {
sl@0: return (std::numeric_limits<std::streamsize>::max)();
sl@0: }
sl@0:
sl@0: // --- data ---
sl@0: int argN_; //- argument number (starts at 0, eg : %1 => argN=0)
sl@0: // negative values for items that don't process an argument
sl@0: string_type res_; //- result of the formatting of this item
sl@0: string_type appendix_; //- piece of string between this item and the next
sl@0:
sl@0: stream_format_state fmtstate_;// set by parsing, is only affected by modify_item
sl@0:
sl@0: std::streamsize truncate_;//- is set for directives like %.5s that ask truncation
sl@0: unsigned int pad_scheme_;//- several possible padding schemes can mix. see pad_values
sl@0: };
sl@0:
sl@0:
sl@0:
sl@0: //--- Definitions ------------------------------------------------------------
sl@0:
sl@0: // - stream_format_state:: -------------------------------------------------
sl@0: template<class Ch, class Tr>
sl@0: void stream_format_state<Ch,Tr>:: apply_on (basic_ios & os,
sl@0: boost::io::detail::locale_t * loc_default) const {
sl@0: // set the state of this stream according to our params
sl@0: if(width_ != -1)
sl@0: os.width(width_);
sl@0: if(precision_ != -1)
sl@0: os.precision(precision_);
sl@0: if(fill_ != 0)
sl@0: os.fill(fill_);
sl@0: os.flags(flags_);
sl@0: os.clear(rdstate_);
sl@0: os.exceptions(exceptions_);
sl@0: #if !defined(BOOST_NO_STD_LOCALE)
sl@0: if(loc_)
sl@0: os.imbue(loc_.get());
sl@0: else if(loc_default)
sl@0: os.imbue(*loc_default);
sl@0: #endif
sl@0: }
sl@0:
sl@0: template<class Ch, class Tr>
sl@0: void stream_format_state<Ch,Tr>:: set_by_stream(const basic_ios& os) {
sl@0: // set our params according to the state of this stream
sl@0: flags_ = os.flags();
sl@0: width_ = os.width();
sl@0: precision_ = os.precision();
sl@0: fill_ = os.fill();
sl@0: rdstate_ = os.rdstate();
sl@0: exceptions_ = os.exceptions();
sl@0: }
sl@0:
sl@0:
sl@0: template<class Ch, class Tr, class T>
sl@0: void apply_manip_body( stream_format_state<Ch, Tr>& self,
sl@0: T manipulator) {
sl@0: // modify our params according to the manipulator
sl@0: basic_oaltstringstream<Ch, Tr> ss;
sl@0: self.apply_on( ss );
sl@0: ss << manipulator;
sl@0: self.set_by_stream( ss );
sl@0: }
sl@0:
sl@0: template<class Ch, class Tr> inline
sl@0: void stream_format_state<Ch,Tr>:: reset(Ch fill) {
sl@0: // set our params to standard's default state. cf ยง 27.4.4.1 of the C++ norm
sl@0: width_=0; precision_=6;
sl@0: fill_=fill; // default is widen(' '), but we cant compute it without the locale
sl@0: flags_ = std::ios_base::dec | std::ios_base::skipws;
sl@0: // the adjust_field part is left equal to 0, which means right.
sl@0: exceptions_ = std::ios_base::goodbit;
sl@0: rdstate_ = std::ios_base::goodbit;
sl@0: }
sl@0:
sl@0:
sl@0: // --- format_item:: --------------------------------------------------------
sl@0:
sl@0: template<class Ch, class Tr, class Alloc>
sl@0: void format_item<Ch, Tr, Alloc>::
sl@0: reset (Ch fill) {
sl@0: argN_=argN_no_posit; truncate_ = max_streamsize(); pad_scheme_ =0;
sl@0: res_.resize(0); appendix_.resize(0);
sl@0: fmtstate_.reset(fill);
sl@0: }
sl@0:
sl@0: template<class Ch, class Tr, class Alloc>
sl@0: void format_item<Ch, Tr, Alloc>::
sl@0: compute_states() {
sl@0: // reflect pad_scheme_ on fmt_state_
sl@0: // because some pad_schemes has complex consequences on several state params.
sl@0: if(pad_scheme_ & zeropad) {
sl@0: // ignore zeropad in left alignment :
sl@0: if(fmtstate_.flags_ & std::ios_base::left) {
sl@0: BOOST_ASSERT(!(fmtstate_.flags_ &(std::ios_base::adjustfield ^std::ios_base::left)));
sl@0: // only left bit might be set. (not right, nor internal)
sl@0: pad_scheme_ = pad_scheme_ & (~zeropad);
sl@0: }
sl@0: else {
sl@0: pad_scheme_ &= ~spacepad; // printf ignores spacepad when zeropadding
sl@0: fmtstate_.fill_='0';
sl@0: fmtstate_.flags_ = (fmtstate_.flags_ & ~std::ios_base::adjustfield)
sl@0: | std::ios_base::internal;
sl@0: // removes all adjustfield bits, and adds internal.
sl@0: }
sl@0: }
sl@0: if(pad_scheme_ & spacepad) {
sl@0: if(fmtstate_.flags_ & std::ios_base::showpos)
sl@0: pad_scheme_ &= ~spacepad;
sl@0: }
sl@0: }
sl@0:
sl@0:
sl@0: } } } // namespaces boost :: io :: detail
sl@0:
sl@0:
sl@0: #endif // BOOST_FORMAT_INTERNALS_HPP