ostrstream

ostrstreambasic_ostreambasic_iosios_base

• Summary
• Data Type and Member Function Indexes
• Synopsis
• Description
• Interface
• Types
• Constructors
• Destructors
• Member Functions
• Example
• See Also
• Standards Conformance

Writes to an array in memory.

Data Types
char_type int_type off_type pos_type	traits

Member Functions

freeze() pcount() rdbuf() str()

#include <strstream> 
class ostrstream
: public basic_ostream<char>

The class ostrstream writes to an array in memory. It uses a private strstreambuf object to control the associated array object. It inherits from basic_ostream<char> and therefore can use all the formatted and unformatted output functions.

This is a deprecated feature and might not be available in future versions.

class ostrstream 
: public basic_ostream<char> {

 public:

  typedef char_traits<char>             traits;

  typedef char                         char_type;
  typedef typename traits::int_type    int_type;
  typedef typename traits::pos_type    pos_type;
  typedef typename traits::off_type    off_type;

  ostrstream();
  ostrstream(char *s, int n,
             ios_base::openmode = ios_base::out);
    
  virtual ~ostrstream();

  strstreambuf *rdbuf() const;
  void freeze(int freezefl = 1);
  char *str();
  int pcount() const;

};

char_type

The type char_type is a synonym of type char.

int_type

The type int_type is a synonym of type traits::in_type.

off_type

The type off_type is a synonym of type traits::off_type.

pos_type

The type pos_type is a synonym of type traits::pos_type.

traits

The type traits is a synonym of type char_traits<char>.

ostrstream();

Constructs an object of class ostrstream, initializing the base class basic_ostream<char> with the associated strstreambuf object. The strstreambuf object is initialized by calling its default constructor strstreambuf().

ostrstream(char* s, int n, ios_base::openmode
           mode = ios_base::out); 

Constructs an object of class ostrstream, initializing the base class basic_ostream<char> with the associated strstreambuf object. The strstreambuf object is initialized by calling one of two constructors:

• If mode & app == 0, it calls strstreambuf(s,n,s)

• Otherwise it calls strstreambuf(s,n,s + ::strlen(s))

virtual ~ostrstream();

Destroys an object of class ostrstream.

void 
freeze(bool freezefl = 1); 

If the mode is dynamic, alters the freeze status of the dynamic array object as follows:

• If freezefl is false, the function sets the freeze status to frozen.

• Otherwise, it clears the freeze status.

int
pcount() const; 

Returns the size of the output sequence.

strstreambuf* 
rdbuf() const; 

Returns a pointer to the private strstreambuf object associated with the stream.

char* 
str();

Returns a pointer to the underlying array object, which may be null.

See strstream, istrstream and strstreambuf examples.

char_traits(3C++), ios_base(3C++), basic_ios(3C++), strstreambuf(3C++), istrstream(3C++), strstream(3C++)

Working Paper for Draft Proposed International Standard for Information Systems--Programming Language C++, Annex D Compatibility features Section D.6.3

ANSI X3J16/ISO WG21 Joint C++ Committee