You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
203 lines
8.0 KiB
203 lines
8.0 KiB
// ---------------------------------------------------------------------------- |
|
// internals.hpp : internal structs : stream_format_state, format_item. |
|
// included by format.hpp |
|
// ---------------------------------------------------------------------------- |
|
|
|
// Copyright Samuel Krempp 2003. Use, modification, and distribution are |
|
// subject to the Boost Software License, Version 1.0. (See accompanying |
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
|
|
|
// See http://www.boost.org/libs/format for library home page |
|
|
|
// ---------------------------------------------------------------------------- |
|
|
|
#ifndef BOOST_FORMAT_INTERNALS_HPP |
|
#define BOOST_FORMAT_INTERNALS_HPP |
|
|
|
|
|
#include <string> |
|
#include <boost/assert.hpp> |
|
#include <boost/core/ignore_unused.hpp> |
|
#include <boost/optional.hpp> |
|
#include <boost/limits.hpp> |
|
#include <boost/format/detail/compat_workarounds.hpp> |
|
#include <boost/format/alt_sstream.hpp> // used as a dummy stream |
|
|
|
namespace boost { |
|
namespace io { |
|
namespace detail { |
|
|
|
|
|
//---- stream_format_state --------------------------------------------------// |
|
|
|
// set of params that define the format state of a stream |
|
template<class Ch, class Tr> |
|
struct stream_format_state |
|
{ |
|
typedef BOOST_IO_STD basic_ios<Ch, Tr> basic_ios; |
|
|
|
stream_format_state(Ch fill) { reset(fill); } |
|
// stream_format_state(const basic_ios& os) { set_by_stream(os); } |
|
|
|
void reset(Ch fill); //- sets to default state. |
|
void set_by_stream(const basic_ios& os); //- sets to os's state. |
|
void apply_on(basic_ios & os, //- applies format_state to the stream |
|
boost::io::detail::locale_t * loc_default = 0) const; |
|
template<class T> |
|
void apply_manip(T manipulator) //- modifies state by applying manipulator |
|
{ apply_manip_body<Ch, Tr, T>( *this, manipulator) ; } |
|
|
|
// --- data --- |
|
std::streamsize width_; |
|
std::streamsize precision_; |
|
Ch fill_; |
|
std::ios_base::fmtflags flags_; |
|
std::ios_base::iostate rdstate_; |
|
std::ios_base::iostate exceptions_; |
|
boost::optional<boost::io::detail::locale_t> loc_; |
|
}; |
|
|
|
|
|
//---- format_item ---------------------------------------------------------// |
|
|
|
// stores all parameters that can be specified in format strings |
|
template<class Ch, class Tr, class Alloc> |
|
struct format_item |
|
{ |
|
enum pad_values { zeropad = 1, spacepad =2, centered=4, tabulation = 8 }; |
|
// 1. if zeropad is set, all other bits are not, |
|
// 2. if tabulation is set, all others are not. |
|
// centered and spacepad can be mixed freely. |
|
enum arg_values { argN_no_posit = -1, // non-positional directive. will set argN later |
|
argN_tabulation = -2, // tabulation directive. (no argument read) |
|
argN_ignored = -3 // ignored directive. (no argument read) |
|
}; |
|
typedef BOOST_IO_STD basic_ios<Ch, Tr> basic_ios; |
|
typedef detail::stream_format_state<Ch, Tr> stream_format_state; |
|
typedef ::std::basic_string<Ch, Tr, Alloc> string_type; |
|
|
|
format_item(Ch fill) :argN_(argN_no_posit), fmtstate_(fill), |
|
truncate_(max_streamsize()), pad_scheme_(0) {} |
|
void reset(Ch fill); |
|
void compute_states(); // sets states according to truncate and pad_scheme. |
|
|
|
static std::streamsize max_streamsize() { |
|
return (std::numeric_limits<std::streamsize>::max)(); |
|
} |
|
|
|
// --- data --- |
|
int argN_; //- argument number (starts at 0, eg : %1 => argN=0) |
|
// negative values for items that don't process an argument |
|
string_type res_; //- result of the formatting of this item |
|
string_type appendix_; //- piece of string between this item and the next |
|
|
|
stream_format_state fmtstate_;// set by parsing, is only affected by modify_item |
|
|
|
std::streamsize truncate_;//- is set for directives like %.5s that ask truncation |
|
unsigned int pad_scheme_;//- several possible padding schemes can mix. see pad_values |
|
}; |
|
|
|
|
|
|
|
//--- Definitions ------------------------------------------------------------ |
|
|
|
// - stream_format_state:: ------------------------------------------------- |
|
template<class Ch, class Tr> |
|
void stream_format_state<Ch,Tr>:: apply_on (basic_ios & os, |
|
boost::io::detail::locale_t * loc_default) const { |
|
// If a locale is available, set it first. "os.fill(fill_);" may chrash otherwise. |
|
#if !defined(BOOST_NO_STD_LOCALE) |
|
if(loc_) |
|
os.imbue(loc_.get()); |
|
else if(loc_default) |
|
os.imbue(*loc_default); |
|
#else |
|
ignore_unused(loc_default); |
|
#endif |
|
// set the state of this stream according to our params |
|
if(width_ != -1) |
|
os.width(width_); |
|
if(precision_ != -1) |
|
os.precision(precision_); |
|
if(fill_ != 0) |
|
os.fill(fill_); |
|
os.flags(flags_); |
|
os.clear(rdstate_); |
|
os.exceptions(exceptions_); |
|
} |
|
|
|
template<class Ch, class Tr> |
|
void stream_format_state<Ch,Tr>:: set_by_stream(const basic_ios& os) { |
|
// set our params according to the state of this stream |
|
flags_ = os.flags(); |
|
width_ = os.width(); |
|
precision_ = os.precision(); |
|
fill_ = os.fill(); |
|
rdstate_ = os.rdstate(); |
|
exceptions_ = os.exceptions(); |
|
} |
|
|
|
|
|
template<class Ch, class Tr, class T> |
|
void apply_manip_body( stream_format_state<Ch, Tr>& self, |
|
T manipulator) { |
|
// modify our params according to the manipulator |
|
basic_oaltstringstream<Ch, Tr> ss; |
|
self.apply_on( ss ); |
|
ss << manipulator; |
|
self.set_by_stream( ss ); |
|
} |
|
|
|
template<class Ch, class Tr> inline |
|
void stream_format_state<Ch,Tr>:: reset(Ch fill) { |
|
// set our params to standard's default state. cf 27.4.4.1 of the C++ norm |
|
width_=0; precision_=6; |
|
fill_=fill; // default is widen(' '), but we cant compute it without the locale |
|
flags_ = std::ios_base::dec | std::ios_base::skipws; |
|
// the adjust_field part is left equal to 0, which means right. |
|
exceptions_ = std::ios_base::goodbit; |
|
rdstate_ = std::ios_base::goodbit; |
|
} |
|
|
|
|
|
// --- format_item:: -------------------------------------------------------- |
|
|
|
template<class Ch, class Tr, class Alloc> |
|
void format_item<Ch, Tr, Alloc>:: |
|
reset (Ch fill) { |
|
argN_=argN_no_posit; truncate_ = max_streamsize(); pad_scheme_ =0; |
|
res_.resize(0); appendix_.resize(0); |
|
fmtstate_.reset(fill); |
|
} |
|
|
|
template<class Ch, class Tr, class Alloc> |
|
void format_item<Ch, Tr, Alloc>:: |
|
compute_states() { |
|
// reflect pad_scheme_ on fmt_state_ |
|
// because some pad_schemes has complex consequences on several state params. |
|
if(pad_scheme_ & zeropad) { |
|
// ignore zeropad in left alignment : |
|
if(fmtstate_.flags_ & std::ios_base::left) { |
|
BOOST_ASSERT(!(fmtstate_.flags_ &(std::ios_base::adjustfield ^std::ios_base::left))); |
|
// only left bit might be set. (not right, nor internal) |
|
pad_scheme_ = pad_scheme_ & (~zeropad); |
|
} |
|
else { |
|
pad_scheme_ &= ~spacepad; // printf ignores spacepad when zeropadding |
|
fmtstate_.fill_='0'; |
|
fmtstate_.flags_ = (fmtstate_.flags_ & ~std::ios_base::adjustfield) |
|
| std::ios_base::internal; |
|
// removes all adjustfield bits, and adds internal. |
|
} |
|
} |
|
if(pad_scheme_ & spacepad) { |
|
if(fmtstate_.flags_ & std::ios_base::showpos) |
|
pad_scheme_ &= ~spacepad; |
|
} |
|
} |
|
|
|
|
|
} } } // namespaces boost :: io :: detail |
|
|
|
|
|
#endif // BOOST_FORMAT_INTERNALS_HPP
|
|
|