Standard library header <strstream>

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Standard Library header files

Language Support
<cstddef> <limits> <climits> <contract>	<cfloat> <cstdint> <new> <version>	<typeinfo> <exception> <initializer_list>	<csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator> <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
Strings
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring> <charconv>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>	<bit>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

This header is part of the Input/Output library.

Classes
strstreambuf (deprecated)	implements raw character array device (class)
istrstream (deprecated)	implements character array input operations (class)
ostrstream (deprecated)	implements character array output operations (class)
strstream (deprecated)	implements character array input/output operations (class)

Synopsis

namespace std {
    class strstreambuf;
    class istrstream;
    class ostrstream;
    class strstream;
}

Class std::strstreambuf

class strstreambuf : public basic_streambuf<char> {
 public:
    explicit strstreambuf(streamsize alsize_arg = 0);
    strstreambuf(void* (*palloc_arg)(size_t), void (*pfree_arg)(void*));
    strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = 0);
    strstreambuf(const char* gnext_arg, streamsize n);
    strstreambuf(signed char* gnext_arg, streamsize n, signed char* pbeg_arg = 0);
    strstreambuf(const signed char* gnext_arg, streamsize n);
    strstreambuf(unsigned char* gnext_arg, streamsize n, unsigned char* pbeg_arg = 0);
    strstreambuf(const unsigned char* gnext_arg, streamsize n);
    virtual ~strstreambuf();

    void freeze(bool freezefl = true);
    char* str();
    int pcount();

 protected:
    virtual int_type overflow (int_type c = EOF);
    virtual int_type pbackfail(int_type c = EOF);
    virtual int_type underflow();
    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
                             ios_base::openmode which = ios_base::in|ios_base::out);
    virtual pos_type seekpos(pos_type sp,
                             ios_base::openmode which = ios_base::in|ios_base::out);
    virtual streambuf* setbuf(char* s, streamsize n);

 private:
    typedef /*bitmask type*/ strstate; // exposition only
    static const strstate allocated; // exposition only
    static const strstate constant; // exposition only
    static const strstate dynamic; // exposition only
    static const strstate frozen; // exposition only
    strstate strmode; // exposition only
    streamsize alsize; // exposition only
    void* (*palloc)(size_t); // exposition only
    void (*pfree)(void*); // exposition only
};

Class std::istrstream

class istrstream : public basic_istream<char> {
 public:
    explicit istrstream(const char* s);
    explicit istrstream(char* s);
    istrstream(const char* s, streamsize n);
    istrstream(char* s, streamsize n);
    virtual ~istrstream();

    strstreambuf* rdbuf() const;
    char *str();

 private:
    strstreambuf sb; // exposition only
};

Class std::ostrstream

class ostrstream : public basic_ostream<char> {
 public:
    ostrstream();
    ostrstream(char* s, int n, ios_base::openmode mode = ios_base::out);
    virtual ~ostrstream();

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

 private:
    strstreambuf sb; // exposition only
};

Class std::strstream

class strstream : public basic_iostream<char> {
 public:
    // Types
    typedef char char_type;
    typedef typename char_traits<char>::int_type int_type;
    typedef typename char_traits<char>::pos_type pos_type;
    typedef typename char_traits<char>::off_type off_type;

    // constructors/destructor
    strstream();
    strstream(char* s, int n,
    ios_base::openmode mode = ios_base::in