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

539 lines
18 KiB
C++

// Output streams -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
// 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: 27.6.2 Output streams
//
/** @file ostream
* 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_OSTREAM
#define _CPP_OSTREAM 1
#pragma GCC system_header
#include <ios>
namespace std
{
// [27.6.2.1] Template class basic_ostream
/**
* @brief Controlling output.
*
* This is the base class for all output streams. It provides text
* formatting of all builtin types, and communicates with any class
* derived from basic_streambuf to do the actual output.
*/
template<typename _CharT, typename _Traits>
class basic_ostream : virtual public basic_ios<_CharT, _Traits>
{
public:
// Types (inherited from basic_ios (27.4.4)):
typedef _CharT char_type;
typedef typename _Traits::int_type int_type;
typedef typename _Traits::pos_type pos_type;
typedef typename _Traits::off_type off_type;
typedef _Traits traits_type;
// Non-standard Types:
typedef basic_streambuf<_CharT, _Traits> __streambuf_type;
typedef basic_ios<_CharT, _Traits> __ios_type;
typedef basic_ostream<_CharT, _Traits> __ostream_type;
typedef ostreambuf_iterator<_CharT, _Traits> __ostreambuf_iter;
typedef num_put<_CharT, __ostreambuf_iter> __numput_type;
typedef ctype<_CharT> __ctype_type;
template<typename _CharT2, typename _Traits2>
friend basic_ostream<_CharT2, _Traits2>&
operator<<(basic_ostream<_CharT2, _Traits2>&, _CharT2);
template<typename _Traits2>
friend basic_ostream<char, _Traits2>&
operator<<(basic_ostream<char, _Traits2>&, char);
template<typename _CharT2, typename _Traits2>
friend basic_ostream<_CharT2, _Traits2>&
operator<<(basic_ostream<_CharT2, _Traits2>&, const _CharT2*);
template<typename _Traits2>
friend basic_ostream<char, _Traits2>&
operator<<(basic_ostream<char, _Traits2>&, const char*);
template<typename _CharT2, typename _Traits2>
friend basic_ostream<_CharT2, _Traits2>&
operator<<(basic_ostream<_CharT2, _Traits2>&, const char*);
// [27.6.2.2] constructor/destructor
/**
* @brief Base constructor.
*
* This ctor is almost never called by the user directly, rather from
* derived classes' initialization lists, which pass a pointer to
* their own stream buffer.
*/
explicit
basic_ostream(__streambuf_type* __sb)
{ this->init(__sb); }
/**
* @brief Base destructor.
*
* This does very little apart from providing a virtual base dtor.
*/
virtual
~basic_ostream() { }
// [27.6.2.3] prefix/suffix
class sentry;
friend class sentry;
// [27.6.2.5] formatted output
// [27.6.2.5.3] basic_ostream::operator<<
//@{
/**
* @brief Interface for manipulators.
*
* Manuipulators such as @c std::endl and @c std::hex use these
* functions in constructs like "std::cout << std::endl". For more
* information, see the iomanip header.
*/
__ostream_type&
operator<<(__ostream_type& (*__pf)(__ostream_type&));
__ostream_type&
operator<<(__ios_type& (*__pf)(__ios_type&));
__ostream_type&
operator<<(ios_base& (*__pf) (ios_base&));
//@}
// [27.6.2.5.2] arithmetic inserters
/**
* @name Arithmetic Inserters
*
* All the @c operator<< functions (aka <em>formatted output
* functions</em>) have some common behavior. Each starts by
* constructing a temporary object of type std::basic_ostream::sentry.
* This can have several effects, concluding with the setting of a
* status flag; see the sentry documentation for more.
*
* If the sentry status is good, the function tries to generate
* whatever data is appropriate for the type of the argument.
*
* If an exception is thrown during insertion, ios_base::badbit
* will be turned on in the stream's error state without causing an
* ios_base::failure to be thrown. The original exception will then
* be rethrown.
*/
//@{
/**
* @brief Basic arithmetic inserters
* @param A variable of builtin type.
* @return @c *this if successful
*
* These functions use the stream's current locale (specifically, the
* @c num_get facet) to perform numeric formatting.
*/
__ostream_type&
operator<<(long __n);
__ostream_type&
operator<<(unsigned long __n);
__ostream_type&
operator<<(bool __n);
__ostream_type&
operator<<(short __n)
{
ios_base::fmtflags __fmt = this->flags() & ios_base::basefield;
if (__fmt & ios_base::oct || __fmt & ios_base::hex)
return this->operator<<(static_cast<unsigned long>
(static_cast<unsigned short>(__n)));
else
return this->operator<<(static_cast<long>(__n));
}
__ostream_type&
operator<<(unsigned short __n)
{ return this->operator<<(static_cast<unsigned long>(__n)); }
__ostream_type&
operator<<(int __n)
{
ios_base::fmtflags __fmt = this->flags() & ios_base::basefield;
if (__fmt & ios_base::oct || __fmt & ios_base::hex)
return this->operator<<(static_cast<unsigned long>
(static_cast<unsigned int>(__n)));
else
return this->operator<<(static_cast<long>(__n));
}
__ostream_type&
operator<<(unsigned int __n)
{ return this->operator<<(static_cast<unsigned long>(__n)); }
#ifdef _GLIBCPP_USE_LONG_LONG
__ostream_type&
operator<<(long long __n);
__ostream_type&
operator<<(unsigned long long __n);
#endif
__ostream_type&
operator<<(double __f);
__ostream_type&
operator<<(float __f)
{ return this->operator<<(static_cast<double>(__f)); }
__ostream_type&
operator<<(long double __f);
__ostream_type&
operator<<(const void* __p);
/**
* @brief Extracting from another streambuf.
* @param sb A pointer to a streambuf
*
* This function behaves like one of the basic arithmetic extractors,
* in that it also constructs a sentry onject and has the same error
* handling behavior.
*
* If @a sb is NULL, the stream will set failbit in its error state.
*
* Characters are extracted from @a sb and inserted into @c *this
* until one of the following occurs:
*
* - the input stream reaches end-of-file,
* - insertion into the output sequence fails (in this case, the
* character that would have been inserted is not extracted), or
* - an exception occurs while getting a character from @a sb, which
* sets failbit in the error state
*
* If the function inserts no characters, failbit is set.
*/
__ostream_type&
operator<<(__streambuf_type* __sb);
//@}
// [27.6.2.6] unformatted output functions
/**
* @name Unformatted Output Functions
*
* All the unformatted output functions have some common behavior.
* Each starts by constructing a temporary object of type
* std::basic_ostream::sentry. This has several effects, concluding
* with the setting of a status flag; see the sentry documentation
* for more.
*
* If the sentry status is good, the function tries to generate
* whatever data is appropriate for the type of the argument.
*
* If an exception is thrown during insertion, ios_base::badbit
* will be turned on in the stream's error state. If badbit is on in
* the stream's exceptions mask, the exception will be rethrown
* without completing its actions.
*/
//@{
/**
* @brief Simple insertion.
* @param c The character to insert.
* @return *this
*
* Tries to insert @a c.
*
* @note This function is not overloaded on signed char and
* unsigned char.
*/
__ostream_type&
put(char_type __c);
/**
* @brief Character string insertion.
* @param s The array to insert.
* @param n Maximum number of characters to insert.
* @return *this
*
* Characters are copied from @a s and inserted into the stream until
* one of the following happens:
*
* - @a n characters are inserted
* - inserting into the output sequence fails (in this case, badbit
* will be set in the stream's error state)
*
* @note This function is not overloaded on signed char and
* unsigned char.
*/
__ostream_type&
write(const char_type* __s, streamsize __n);
//@}
/**
* @brief Synchronizing the stream buffer.
* @return *this
*
* If @c rdbuf() is a null pointer, changes nothing.
*
* Otherwise, calls @c rdbuf()->pubsync(), and if that returns -1,
* sets badbit.
*/
__ostream_type&
flush();
// [27.6.2.4] seek members
/**
* @brief Getting the current write position.
* @return A file position object.
*
* If @c fail() is not false, returns @c pos_type(-1) to indicate
* failure. Otherwise returns @c rdbuf()->pubseekoff(0,cur,out).
*/
pos_type
tellp();
/**
* @brief Changing the current write position.
* @param pos A file position object.
* @return *this
*
* If @c fail() is not true, calls @c rdbuf()->pubseekpos(pos). If
* that function fails, sets failbit.
*/
__ostream_type&
seekp(pos_type);
/**
* @brief Changing the current write position.
* @param off A file offset object.
* @param dir The direction in which to seek.
* @return *this
*
* If @c fail() is not true, calls @c rdbuf()->pubseekoff(off,dir).
* If that function fails, sets failbit.
*/
__ostream_type&
seekp(off_type, ios_base::seekdir);
};
/**
* @brief Performs setup work for output streams.
*
* Objects of this class are created before all of the standard
* inserters are run. It is responsible for "exception-safe prefix and
* suffix operations." Additional actions may be added by the
* implementation, and we list them in
* http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#5
* under [27.6] notes.
*/
template <typename _CharT, typename _Traits>
class basic_ostream<_CharT, _Traits>::sentry
{
// Data Members:
bool _M_ok;
basic_ostream<_CharT,_Traits>& _M_os;
public:
/**
* @brief The constructor performs preparatory work.
* @param os The output stream to guard.
*
* If the stream state is good (@a os.good() is true), then if the
* stream is tied to another output stream, @c is.tie()->flush()
* is called to synchronize the output sequences.
*
* If the stream state is still good, then the sentry state becomes
* true ("okay").
*/
explicit
sentry(basic_ostream<_CharT,_Traits>& __os);
/**
* @brief Possibly flushes the stream.
*
* If @c ios_base::unitbuf is set in @c os.flags(), and
* @c std::uncaught_exception() is true, the sentry destructor calls
* @c flush() on the output stream.
*/
~sentry()
{
// XXX MT
if (_M_os.flags() & ios_base::unitbuf && !uncaught_exception())
{
// Can't call flush directly or else will get into recursive lock.
if (_M_os.rdbuf() && _M_os.rdbuf()->pubsync() == -1)
_M_os.setstate(ios_base::badbit);
}
}
/**
* @brief Quick status checking.
* @return The sentry state.
*
* For ease of use, sentries may be converted to booleans. The
* return value is that of the sentry state (true == okay).
*/
operator bool()
{ return _M_ok; }
};
// [27.6.2.5.4] character insertion templates
//@{
/**
* @brief Character inserters
* @param out An output stream.
* @param c A character.
* @return out
*
* Behaves like one of the formatted arithmetic inserters described in
* std::basic_ostream. After constructing a sentry object with good
* status, this function inserts a single character and any required
* padding (as determined by [22.2.2.2.2]). @c out.width(0) is then
* called.
*
* If @a c is of type @c char and the character type of the stream is not
* @c char, the character is widened before insertion.
*/
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c);
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __out, char __c)
{ return (__out << __out.widen(__c)); }
// Specialization
template <class _Traits>
basic_ostream<char, _Traits>&
operator<<(basic_ostream<char, _Traits>& __out, char __c);
// Signed and unsigned
template<class _Traits>
basic_ostream<char, _Traits>&
operator<<(basic_ostream<char, _Traits>& __out, signed char __c)
{ return (__out << static_cast<char>(__c)); }
template<class _Traits>
basic_ostream<char, _Traits>&
operator<<(basic_ostream<char, _Traits>& __out, unsigned char __c)
{ return (__out << static_cast<char>(__c)); }
//@}
//@{
/**
* @brief String inserters
* @param out An output stream.
* @param s A character string.
* @return out
* @pre @a s must be a non-NULL pointer
*
* Behaves like one of the formatted arithmetic inserters described in
* std::basic_ostream. After constructing a sentry object with good
* status, this function inserts @c traits::length(s) characters starting
* at @a s, widened if necessary, followed by any required padding (as
* determined by [22.2.2.2.2]). @c out.width(0) is then called.
*/
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s);
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits> &
operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s);
// Partial specializationss
template<class _Traits>
basic_ostream<char, _Traits>&
operator<<(basic_ostream<char, _Traits>& __out, const char* __s);
// Signed and unsigned
template<class _Traits>
basic_ostream<char, _Traits>&
operator<<(basic_ostream<char, _Traits>& __out, const signed char* __s)
{ return (__out << reinterpret_cast<const char*>(__s)); }
template<class _Traits>
basic_ostream<char, _Traits> &
operator<<(basic_ostream<char, _Traits>& __out, const unsigned char* __s)
{ return (__out << reinterpret_cast<const char*>(__s)); }
//@}
// [27.6.2.7] standard basic_ostream manipulators
/**
* @brief Write a newline and flush the stream.
*
* This manipulator is often mistakenly used when a simple newline is
* desired, leading to poor buffering performance. See
* http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for more
* on this subject.
*/
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
endl(basic_ostream<_CharT, _Traits>& __os)
{ return flush(__os.put(__os.widen('\n'))); }
/**
* @brief Write a null character into the output sequence.
*
* "Null character" is @c CharT() by definition. For CharT of @c char,
* this correctly writes the ASCII @c NUL character string terminator.
*/
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
ends(basic_ostream<_CharT, _Traits>& __os)
{ return __os.put(_CharT()); }
/**
* @brief Flushes the output stream.
*
* This manipulator simply calls the stream's @c flush() member function.
*/
template<typename _CharT, typename _Traits>
basic_ostream<_CharT, _Traits>&
flush(basic_ostream<_CharT, _Traits>& __os)
{ return __os.flush(); }
} // namespace std
#ifdef _GLIBCPP_NO_TEMPLATE_EXPORT
# define export
#endif
#ifdef _GLIBCPP_FULLY_COMPLIANT_HEADERS
# include <bits/ostream.tcc>
#endif
#endif /* _CPP_OSTREAM */