freebsd-dev/contrib/libstdc++/include/std/std_sstream.h
2003-07-11 03:42:04 +00:00

639 lines
20 KiB
C++

// String based streams -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
//
// ISO C++ 14882: 27.7 String-based streams
//
/** @file sstream
* This is a Standard C++ Library header. You should @c #include this header
* in your programs, rather than any of the "st[dl]_*.h" implementation files.
*/
#ifndef _CPP_SSTREAM
#define _CPP_SSTREAM 1
#pragma GCC system_header
#include <istream>
#include <ostream>
namespace std
{
// [27.7.1] template class basic_stringbuf
/**
* @brief The actual work of input and output (for std::string).
*
* This class associates either or both of its input and output sequences
* with a sequence of characters, which can be initialized from, or made
* available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.)
*
* For this class, open modes (of type @c ios_base::openmode) have
* @c in set if the input sequence can be read, and @c out set if the
* output sequence can be written.
*/
template<typename _CharT, typename _Traits, typename _Alloc>
class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
{
public:
// Types:
typedef _CharT char_type;
typedef _Traits traits_type;
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 251. basic_stringbuf missing allocator_type
typedef _Alloc allocator_type;
#endif
typedef typename traits_type::int_type int_type;
typedef typename traits_type::pos_type pos_type;
typedef typename traits_type::off_type off_type;
//@{
/**
* @if maint
* @doctodo
* @endif
*/
typedef basic_streambuf<char_type, traits_type> __streambuf_type;
typedef basic_string<char_type, _Traits, _Alloc> __string_type;
typedef typename __string_type::size_type __size_type;
//@}
protected:
// Data Members:
/**
* @if maint
* @doctodo
* @endif
*/
__string_type _M_string;
public:
// Constructors:
/**
* @brief Starts with an empty string buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* The default constructor initializes the parent class using its
* own default ctor.
*/
explicit
basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)
: __streambuf_type(), _M_string()
{ _M_stringbuf_init(__mode); }
/**
* @brief Starts with an existing string buffer.
* @param str A string to copy as a starting buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* This constructor initializes the parent class using its
* own default ctor.
*/
explicit
basic_stringbuf(const __string_type& __str,
ios_base::openmode __mode = ios_base::in | ios_base::out)
: __streambuf_type(), _M_string(__str.data(), __str.size())
{ _M_stringbuf_init(__mode); }
// Get and set:
/**
* @brief Copying out the string buffer.
* @return A copy of one of the underlying sequences.
*
* "If the buffer is only created in input mode, the underlying
* character sequence is equal to the input sequence; otherwise, it
* is equal to the output sequence." [27.7.1.2]/1
*/
__string_type
str() const
{
if (_M_mode & ios_base::out)
{
// This is the deal: _M_string.size() is a value that
// represents the size of the initial string that makes
// _M_string, and may not be the correct size of the
// current stringbuf internal buffer.
__size_type __len = _M_string.size();
if (_M_out_end > _M_out_beg)
__len = max(__size_type(_M_out_end - _M_out_beg), __len);
return __string_type(_M_out_beg, _M_out_beg + __len);
}
else
return _M_string;
}
/**
* @brief Setting a new buffer.
* @param s The string to use as a new sequence.
*
* Deallocates any previous stored sequence, then copies @a s to
* use as a new one.
*/
void
str(const __string_type& __s)
{
// Cannot use _M_string = __s, since v3 strings are COW.
_M_string.assign(__s.data(), __s.size());
_M_stringbuf_init(_M_mode);
}
protected:
// Common initialization code for both ctors goes here.
/**
* @if maint
* @doctodo
* @endif
*/
void
_M_stringbuf_init(ios_base::openmode __mode)
{
// _M_buf_size is a convenient alias for "what the streambuf
// thinks the allocated size of the string really is." This is
// necessary as ostringstreams are implemented with the
// streambufs having control of the allocation and
// re-allocation of the internal string object, _M_string.
_M_buf_size = _M_string.size();
// NB: Start ostringstream buffers at 512 bytes. This is an
// experimental value (pronounced "arbitrary" in some of the
// hipper english-speaking countries), and can be changed to
// suit particular needs.
_M_buf_size_opt = 512;
_M_mode = __mode;
if (_M_mode & (ios_base::ate | ios_base::app))
_M_really_sync(0, _M_buf_size);
else
_M_really_sync(0, 0);
}
// Overridden virtual functions:
// [documentation is inherited]
virtual int_type
underflow()
{
if (_M_in_cur && _M_in_cur < _M_in_end)
return traits_type::to_int_type(*gptr());
else
return traits_type::eof();
}
// [documentation is inherited]
virtual int_type
pbackfail(int_type __c = traits_type::eof());
// [documentation is inherited]
virtual int_type
overflow(int_type __c = traits_type::eof());
/**
* @brief Manipulates the buffer.
* @param s Pointer to a buffer area.
* @param n Size of @a s.
* @return @c this
*
* If no buffer has already been created, and both @a s and @a n are
* non-zero, then @c s is used as a buffer; see
* http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2
* for more.
*/
virtual __streambuf_type*
setbuf(char_type* __s, streamsize __n)
{
if (__s && __n)
{
_M_string = __string_type(__s, __n);
_M_really_sync(0, 0);
}
return this;
}
// [documentation is inherited]
virtual pos_type
seekoff(off_type __off, ios_base::seekdir __way,
ios_base::openmode __mode = ios_base::in | ios_base::out);
// [documentation is inherited]
virtual pos_type
seekpos(pos_type __sp,
ios_base::openmode __mode = ios_base::in | ios_base::out);
// Internal function for correctly updating the internal buffer
// for a particular _M_string, due to initialization or
// re-sizing of an existing _M_string.
// Assumes: contents of _M_string and internal buffer match exactly.
// __i == _M_in_cur - _M_in_beg
// __o == _M_out_cur - _M_out_beg
/**
* @if maint
* @doctodo
* @endif
*/
virtual int
_M_really_sync(__size_type __i, __size_type __o)
{
char_type* __base = const_cast<char_type*>(_M_string.data());
bool __testin = _M_mode & ios_base::in;
bool __testout = _M_mode & ios_base::out;
__size_type __len = _M_string.size();
_M_buf = __base;
if (__testin)
this->setg(__base, __base + __i, __base + __len);
if (__testout)
{
this->setp(__base, __base + __len);
_M_out_cur += __o;
}
return 0;
}
};
// [27.7.2] Template class basic_istringstream
/**
* @brief Controlling input for std::string.
*
* This class supports reading from objects of type std::basic_string,
* using the inherited functions from std::basic_istream. To control
* the associated sequence, an instance of std::basic_stringbuf is used,
* which this page refers to as @c sb.
*/
template<typename _CharT, typename _Traits, typename _Alloc>
class basic_istringstream : public basic_istream<_CharT, _Traits>
{
public:
// Types:
typedef _CharT char_type;
typedef _Traits traits_type;
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 251. basic_stringbuf missing allocator_type
typedef _Alloc allocator_type;
#endif
typedef typename traits_type::int_type int_type;
typedef typename traits_type::pos_type pos_type;
typedef typename traits_type::off_type off_type;
// Non-standard types:
typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
typedef basic_istream<char_type, traits_type> __istream_type;
private:
/**
* @if maint
* @doctodo
* @endif
*/
__stringbuf_type _M_stringbuf;
public:
// Constructors:
/**
* @brief Default constructor starts with an empty string buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* @c ios_base::in is automatically included in @a mode.
*
* Initializes @c sb using @c mode|in, and passes @c &sb to the base
* class initializer. Does not allocate any buffer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_istringstream(ios_base::openmode __mode = ios_base::in)
: __istream_type(NULL), _M_stringbuf(__mode | ios_base::in)
{ this->init(&_M_stringbuf); }
/**
* @brief Starts with an existing string buffer.
* @param str A string to copy as a starting buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* @c ios_base::in is automatically included in @a mode.
*
* Initializes @c sb using @a str and @c mode|in, and passes @c &sb
* to the base class initializer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_istringstream(const __string_type& __str,
ios_base::openmode __mode = ios_base::in)
: __istream_type(NULL), _M_stringbuf(__str, __mode | ios_base::in)
{ this->init(&_M_stringbuf); }
/**
* @brief The destructor does nothing.
*
* The buffer is deallocated by the stringbuf object, not the
* formatting stream.
*/
~basic_istringstream()
{ }
// Members:
/**
* @brief Accessing the underlying buffer.
* @return The current basic_stringbuf buffer.
*
* This hides both signatures of std::basic_ios::rdbuf().
*/
__stringbuf_type*
rdbuf() const
{ return const_cast<__stringbuf_type*>(&_M_stringbuf); }
/**
* @brief Copying out the string buffer.
* @return @c rdbuf()->str()
*/
__string_type
str() const
{ return _M_stringbuf.str(); }
/**
* @brief Setting a new buffer.
* @param s The string to use as a new sequence.
*
* Calls @c rdbuf()->str(s).
*/
void
str(const __string_type& __s)
{ _M_stringbuf.str(__s); }
};
// [27.7.3] Template class basic_ostringstream
/**
* @brief Controlling output for std::string.
*
* This class supports writing to objects of type std::basic_string,
* using the inherited functions from std::basic_ostream. To control
* the associated sequence, an instance of std::basic_stringbuf is used,
* which this page refers to as @c sb.
*/
template <typename _CharT, typename _Traits, typename _Alloc>
class basic_ostringstream : public basic_ostream<_CharT, _Traits>
{
public:
// Types:
typedef _CharT char_type;
typedef _Traits traits_type;
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 251. basic_stringbuf missing allocator_type
typedef _Alloc allocator_type;
#endif
typedef typename traits_type::int_type int_type;
typedef typename traits_type::pos_type pos_type;
typedef typename traits_type::off_type off_type;
// Non-standard types:
typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
typedef basic_ostream<char_type, traits_type> __ostream_type;
private:
/**
* @if maint
* @doctodo
* @endif
*/
__stringbuf_type _M_stringbuf;
public:
// Constructors/destructor:
/**
* @brief Default constructor starts with an empty string buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* @c ios_base::out is automatically included in @a mode.
*
* Initializes @c sb using @c mode|out, and passes @c &sb to the base
* class initializer. Does not allocate any buffer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_ostringstream(ios_base::openmode __mode = ios_base::out)
: __ostream_type(NULL), _M_stringbuf(__mode | ios_base::out)
{ this->init(&_M_stringbuf); }
/**
* @brief Starts with an existing string buffer.
* @param str A string to copy as a starting buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* @c ios_base::out is automatically included in @a mode.
*
* Initializes @c sb using @a str and @c mode|out, and passes @c &sb
* to the base class initializer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_ostringstream(const __string_type& __str,
ios_base::openmode __mode = ios_base::out)
: __ostream_type(NULL), _M_stringbuf(__str, __mode | ios_base::out)
{ this->init(&_M_stringbuf); }
/**
* @brief The destructor does nothing.
*
* The buffer is deallocated by the stringbuf object, not the
* formatting stream.
*/
~basic_ostringstream()
{ }
// Members:
/**
* @brief Accessing the underlying buffer.
* @return The current basic_stringbuf buffer.
*
* This hides both signatures of std::basic_ios::rdbuf().
*/
__stringbuf_type*
rdbuf() const
{ return const_cast<__stringbuf_type*>(&_M_stringbuf); }
/**
* @brief Copying out the string buffer.
* @return @c rdbuf()->str()
*/
__string_type
str() const
{ return _M_stringbuf.str(); }
/**
* @brief Setting a new buffer.
* @param s The string to use as a new sequence.
*
* Calls @c rdbuf()->str(s).
*/
void
str(const __string_type& __s)
{ _M_stringbuf.str(__s); }
};
// [27.7.4] Template class basic_stringstream
/**
* @brief Controlling input and output for std::string.
*
* This class supports reading from and writing to objects of type
* std::basic_string, using the inherited functions from
* std::basic_iostream. To control the associated sequence, an instance
* of std::basic_stringbuf is used, which this page refers to as @c sb.
*/
template <typename _CharT, typename _Traits, typename _Alloc>
class basic_stringstream : public basic_iostream<_CharT, _Traits>
{
public:
// Types:
typedef _CharT char_type;
typedef _Traits traits_type;
#ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
// 251. basic_stringbuf missing allocator_type
typedef _Alloc allocator_type;
#endif
typedef typename traits_type::int_type int_type;
typedef typename traits_type::pos_type pos_type;
typedef typename traits_type::off_type off_type;
// Non-standard Types:
typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type;
typedef basic_iostream<char_type, traits_type> __iostream_type;
private:
/**
* @if maint
* @doctodo
* @endif
*/
__stringbuf_type _M_stringbuf;
public:
// Constructors/destructors
/**
* @brief Default constructor starts with an empty string buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* Initializes @c sb using @c mode, and passes @c &sb to the base
* class initializer. Does not allocate any buffer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in)
: __iostream_type(NULL), _M_stringbuf(__m)
{ this->init(&_M_stringbuf); }
/**
* @brief Starts with an existing string buffer.
* @param str A string to copy as a starting buffer.
* @param mode Whether the buffer can read, or write, or both.
*
* Initializes @c sb using @a str and @c mode, and passes @c &sb
* to the base class initializer.
*
* @if maint
* That's a lie. We initialize the base class with NULL, because the
* string class does its own memory management.
* @endif
*/
explicit
basic_stringstream(const __string_type& __str,
ios_base::openmode __m = ios_base::out | ios_base::in)
: __iostream_type(NULL), _M_stringbuf(__str, __m)
{ this->init(&_M_stringbuf); }
/**
* @brief The destructor does nothing.
*
* The buffer is deallocated by the stringbuf object, not the
* formatting stream.
*/
~basic_stringstream()
{ }
// Members:
/**
* @brief Accessing the underlying buffer.
* @return The current basic_stringbuf buffer.
*
* This hides both signatures of std::basic_ios::rdbuf().
*/
__stringbuf_type*
rdbuf() const
{ return const_cast<__stringbuf_type*>(&_M_stringbuf); }
/**
* @brief Copying out the string buffer.
* @return @c rdbuf()->str()
*/
__string_type
str() const
{ return _M_stringbuf.str(); }
/**
* @brief Setting a new buffer.
* @param s The string to use as a new sequence.
*
* Calls @c rdbuf()->str(s).
*/
void
str(const __string_type& __s)
{ _M_stringbuf.str(__s); }
};
} // namespace std
#ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
# define export
#endif
#ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS
# include <bits/sstream.tcc>
#endif
#endif