Standard library header <streambuf>

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
basic_streambuf	abstracts a raw device (class template)
Typedefs
streambuf	basic_streambuf<char>
wstreambuf	basic_streambuf<wchar_t>

Synopsis

namespace std {

    template <class charT, class traits = char_traits<charT> >
    class basic_streambuf;

    typedef basic_streambuf<char> streambuf;
    typedef basic_streambuf<wchar_t> wstreambuf;
}

Class std::basic_streambuf

template <class charT, class traits = char_traits<charT> >
class basic_streambuf {
 public:
    // types:
    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;

    virtual ~basic_streambuf();

    // locales:
    locale pubimbue(const locale& loc);
    locale getloc() const;

    // buffer and positioning:
    basic_streambuf<char_type,traits>*
    pubsetbuf(char_type* s, streamsize n);
    pos_type pubseekoff(off_type off, ios_base::seekdir way,
                        ios_base::openmode which = ios_base::in|ios_base::out);
    pos_type pubseekpos(pos_type sp,
                        ios_base::openmode which = ios_base::in|ios_base::out);
    int pubsync();

    // Get area:
    streamsize in_avail();
    int_type snextc();
    int_type sbumpc();
    int_type sgetc();
    streamsize sgetn(char_type* s, streamsize n);

    // Putback:
    int_type sputbackc(char_type c);
    int_type sungetc();

    // Put area:
    int_type sputc(char_type c);
    streamsize sputn(const char_type* s, streamsize n);

 protected:
    basic_streambuf();
    basic_streambuf(const basic_streambuf& rhs);
    basic_streambuf& operator=(const basic_streambuf& rhs);
    void swap(basic_streambuf& rhs);

    // Get area:
    char_type* eback() const;
    char_type* gptr() const;
    char_type* egptr() const;
    void gbump(int n);
    void setg(char_type* gbeg, char_type* gnext, char_type* gend);

    // Put area:
    char_type* pbase() const;
    char_type* pptr() const;
    char_type* epptr() const;
    void pbump(int n);
    void setp(char_type* pbeg, char_type* pend);

    // virtual functions:
    // Locales:
    virtual void imbue(const locale& loc);

    // Buffer management and positioning:
    virtual basic_streambuf<char_type,traits>* setbuf(char_type* s, streamsize n);
    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 int sync();

    // Get area:
    virtual streamsize showmanyc();
    virtual streamsize xsgetn(char_type* s, streamsize n);
    virtual int_type underflow();
    virtual int_type uflow();

    // Putback:
    virtual int_type pbackfail(int_type c = traits::eof());

    // Put area:
    virtual streamsize xsputn(const char_type* s, streamsize n);
    virtual int_type overflow (int_type c = traits::eof());
};