Module: Standard C++ Library Library: Input/output
istrstreambasic_istream
Class that reads characters from an array in memory
#include <strstream>
namespace std {
class istrstream;
}
The class istrstream reads characters from an array in memory. It uses a private strstreambuf object to control the associated array object. It inherits from basic_istream and therefore can use all the formatted and unformatted input functions.
NOTE -- This is a deprecated feature and might not be available in future versions.
namespace std {
class istrstream : public basic_istream<char> {
public:
typedef char char_type;
typedef char_traits<char_type> traits_type;
typedef typename traits_type::int_type int_type;
typedef typename traits_type::pos_type pos_type;
typedef typename traits_type::off_type off_type;
explicit istrstream(const char *s);
istrstream(const char *s, streamsize n);
explicit istrstream(char *s);
istrstream(char *s, streamsize n);
virtual ~istrstream();
strstreambuf *rdbuf() const;
char *str();
};
}
char_type
The type char_type is a synonym of type char.
int_type
The type int_type is a synonym of type traits_type::in_type.
off_type
The type off_type is a synonym of type traits_type::off_type.
pos_type
The type pos_type is a synonym of type traits_type::pos_type.
traits_type
The type traits_type is a synonym of type char_traits<char>.
explicit istrstream(const char* s); explicit istrstream(char* s);
Constructs an object of class istrstream, initializing the base class basic_istream with the associated strstreambuf object. The strstreambuf object is initialized by calling strstreambuf(s,0), where s designates the first element of an NTBS (null terminated byte string).
explicit istrstream(const char* s, streamsize n); explicit istrstream(char* s, streamsize n);
Constructs an object of class istrstream, initializing the base class basic_istream with the associated strstreambuf object. The strstreambuf object is initialized by calling strstreambuf(s,n), where s designates the first element of an array whose length is n elements and n is greater than zero.
virtual ~istrstream();
Destroys an object of class istrstream.
char* str();
Calls rdbuf()->str().
strstreambuf* rdbuf() const;
Returns a pointer to the private strstreambuf object associated with the stream.
//
// istrstream.cpp
//
#include <iostream> // for cout
#include <strstream> // for strstream
int main ()
{
// create two constant istrstream objects and initialize their
// underlying strstreambufs with string literals; the objects
// do not create copies of the literals but use them directly
// for efficiency
std::istrstream a ("Ce n'est pas l'homme qui prend la mer, ");
std::istrstream b ("c'est la mer qui prend l'homme.");
// create a dynamic strstream object
std::strstream out;
// output the contents of the streams into out
out << a.rdbuf () << b.str () << '\n';
// output the contents of out to standard output
std::cout << out.rdbuf () << '\n';
// output the contents of the stream objects to standard output
std::cout << a.str () << '\n' << b.rdbuf () << '\n';
// the dtors of a and b will not release any storage
// since the objects did not allocate any
// the dtor of out will release allocated storage since
// neither freeze() nor str() was called on the object
return 0;
}
Program Output:
Ce n'est pas l'homme qui prend la mer, c'est la mer qui prend l'homme. Ce n'est pas l'homme qui prend la mer, c'est la mer qui prend l'homme.
char_traits, ios_base, basic_ios, strstreambuf, ostrstream, strstream
Deprecated. See ISO/IEC 14882:1998 -- International Standard for Information Systems --Programming Language C++, Annex D Compatibility features Section D.7.2
Copyright (c) 1994-2006 Rogue Wave Software, a Quovadx Division.
Licensed under the Apache License, Version 2.0.
Contact Rogue Wave about documentation or support issues. You can also seek help from other developers through the Apache stdcxx community (see below).