aboutsummaryrefslogtreecommitdiff
path: root/boost/format/internals.hpp
diff options
context:
space:
mode:
authorEelco Dolstra <e.dolstra@tudelft.nl>2003-06-27 13:41:42 +0000
committerEelco Dolstra <e.dolstra@tudelft.nl>2003-06-27 13:41:42 +0000
commitbb03c45ca03e038c8b74fc1410f48d02ade4c59b (patch)
tree131afdf9d4b308e4d1fff6089f2ab1923c862e02 /boost/format/internals.hpp
parentd4c3edfaba91a0e5e1e9528749e5b1e178511a6d (diff)
* Added the Boost format library which provides a safe printf
replacement.
Diffstat (limited to 'boost/format/internals.hpp')
-rw-r--r--boost/format/internals.hpp169
1 files changed, 169 insertions, 0 deletions
diff --git a/boost/format/internals.hpp b/boost/format/internals.hpp
new file mode 100644
index 000000000..52448b731
--- /dev/null
+++ b/boost/format/internals.hpp
@@ -0,0 +1,169 @@
+// -*- C++ -*-
+// Boost general library 'format' ---------------------------
+// See http://www.boost.org for updates, documentation, and revision history.
+
+// (C) Samuel Krempp 2001
+// krempp@crans.ens-cachan.fr
+// Permission to copy, use, modify, sell and
+// distribute this software is granted provided this copyright notice appears
+// in all copies. This software is provided "as is" without express or implied
+// warranty, and with no claim as to its suitability for any purpose.
+
+// ideas taken from Rüdiger Loos's format class
+// and Karl Nelson's ofstream
+
+// ----------------------------------------------------------------------------
+// internals.hpp : internal structs. included by format.hpp
+// stream_format_state, and format_item
+// ----------------------------------------------------------------------------
+
+
+#ifndef BOOST_FORMAT_INTERNALS_HPP
+#define BOOST_FORMAT_INTERNALS_HPP
+
+
+#include <string>
+#include <sstream>
+
+namespace boost {
+namespace io {
+namespace detail {
+
+
+// --------------
+// 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;
+
+ std::streamsize width_;
+ std::streamsize precision_;
+ Ch fill_;
+ std::ios_base::fmtflags flags_;
+
+ stream_format_state() : width_(-1), precision_(-1), fill_(0), flags_(std::ios_base::dec) {}
+ stream_format_state(basic_ios& os) {set_by_stream(os); }
+
+ void apply_on(basic_ios & os) const; //- applies format_state to the stream
+ template<class T> void apply_manip(T manipulator) //- modifies state by applying manipulator.
+ { apply_manip_body<Ch, Tr, T>( *this, manipulator) ; }
+ void reset(); //- sets to default state.
+ void set_by_stream(const basic_ios& os); //- sets to os's state.
+};
+
+
+
+// --------------
+// format_item : stores all parameters that can be defined by directives in the format-string
+
+template<class Ch, class Tr>
+struct format_item
+{
+ enum pad_values { zeropad = 1, spacepad =2, centered=4, tabulation = 8 };
+
+ enum arg_values { argN_no_posit = -1, // non-positional directive. argN will be set 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> string_t;
+ typedef BOOST_IO_STD basic_ostringstream<Ch, Tr> internal_stream_t;
+
+
+ int argN_; //- argument number (starts at 0, eg : %1 => argN=0)
+ // negative values are used for items that don't process
+ // an argument
+ string_t res_; //- result of the formatting of this item
+ string_t appendix_; //- piece of string between this item and the next
+
+ stream_format_state ref_state_;// set by parsing the format_string, is only affected by modify_item
+ stream_format_state state_; // always same as ref_state, _unless_ modified by manipulators 'group(..)'
+
+ // non-stream format-state parameters
+ signed int truncate_; //- is >=0 for directives like %.5s (take 5 chars from the string)
+ unsigned int pad_scheme_; //- several possible padding schemes can mix. see pad_values
+
+ format_item() : argN_(argN_no_posit), truncate_(-1), pad_scheme_(0) {}
+
+ void compute_states(); // sets states according to truncate and pad_scheme.
+};
+
+
+
+// -----------------------------------------------------------
+// Definitions
+// -----------------------------------------------------------
+
+// --- stream_format_state:: -------------------------------------------
+template<class Ch, class Tr> inline
+void stream_format_state<Ch,Tr> ::apply_on(basic_ios & os) const
+ // 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_);
+}
+
+template<class Ch, class Tr> inline
+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();
+}
+
+template<class Ch, class Tr, class T> inline
+void apply_manip_body( stream_format_state<Ch, Tr>& self,
+ T manipulator)
+ // modify our params according to the manipulator
+{
+ BOOST_IO_STD basic_stringstream<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()
+ // set our params to standard's default state
+{
+ width_=-1; precision_=-1; fill_=0;
+ flags_ = std::ios_base::dec;
+}
+
+
+// --- format_items:: -------------------------------------------
+template<class Ch, class Tr> inline
+void format_item<Ch, Tr> ::compute_states()
+ // reflect pad_scheme_ on state_ and ref_state_
+ // because some pad_schemes has complex consequences on several state params.
+{
+ if(pad_scheme_ & zeropad)
+ {
+ if(ref_state_.flags_ & std::ios_base::left)
+ {
+ pad_scheme_ = pad_scheme_ & (~zeropad); // ignore zeropad in left alignment
+ }
+ else
+ {
+ ref_state_.fill_='0';
+ ref_state_.flags_ |= std::ios_base::internal;
+ }
+ }
+ state_ = ref_state_;
+}
+
+
+} } } // namespaces boost :: io :: detail
+
+
+#endif // BOOST_FORMAT_INTERNALS_HPP