Standard library header <streambuf>

 

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Standard library headers

Language support <cfloat> <climits> <compare>(C++20) <contracts>(C++26) <coroutine>(C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint>(C++11) <cstdlib> <exception> <initializer_list>(C++11)    <limits> <new> <source_location>(C++20) <stdfloat>(C++23) <typeinfo> <version>(C++20) Concepts <concepts>(C++20) Diagnostics <cassert> <cerrno> <debugging>(C++26) <stacktrace>(C++23) <stdexcept> <system_error>(C++11) Memory management <memory> <memory_resource>(C++17) <scoped_allocator>(C++11) Metaprogramming <type_traits>(C++11) <ratio>(C++11)

General utilities <any>(C++17) <bitset> <bit>(C++20) <charconv>(C++17) <expected>(C++23) <format>(C++20) <functional> <optional>(C++17) <stdbit.h>(C++26) <tuple>(C++11) <typeindex>(C++11) <utility> <variant>(C++17) Containers <array>(C++11) <deque> <flat_map>(C++23) <flat_set>(C++23) <forward_list>(C++11) <hive>(C++26) <inplace_vector>(C++26)    <list> <map> <mdspan>(C++23) <queue> <set> <span>(C++20) <stack> <unordered_map>(C++11) <unordered_set>(C++11) <vector> Iterators <iterator> Ranges <generator>(C++23) <ranges>(C++20)

Algorithms <algorithm> <numeric> Strings <cctype> <cstring> <cuchar>(C++11) <cwchar> <cwctype> <string_view>(C++17) <string> Text processing <clocale> <codecvt>(C++11/17/26*) <locale> <regex>(C++11) <text_encoding>(C++26)    Numerics <cfenv>(C++11) <cmath> <complex> <linalg>(C++26) <numbers>(C++20) <random>(C++11) <simd>(C++26) <stdckdint.h>(C++26) <valarray> Time <chrono>(C++11) <ctime> C compatibility <ccomplex>(C++11/17/20*) <ciso646>(until C++20) <cstdalign>(C++11/17/20*) <cstdbool>(C++11/17/20*) <ctgmath>(C++11/17/20*)

Input/output <cinttypes>(C++11) <cstdio> <filesystem>(C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print>(C++23) <spanstream>(C++23) <sstream> <streambuf> <strstream>(C++98/26*) <syncstream>(C++20) Concurrency support <atomic>(C++11) <barrier>(C++20) <condition_variable>(C++11) <future>(C++11) <hazard_pointer>(C++26) <latch>(C++20) <mutex>(C++11) <rcu>(C++26) <semaphore>(C++20) <shared_mutex>(C++14) <stdatomic.h>(C++23) <stop_token>(C++20) <thread>(C++11) Execution support <execution>(C++17)

 

This header is part of the Input/Output library.

Classes
basic_streambuf	abstracts a raw device (class template)
streambuf	std::basic_streambuf<char> (typedef)
wstreambuf	std::basic_streambuf<wchar_t> (typedef)

Synopsis

namespace std {template<class CharT, class Traits = char_traits<CharT>>class basic_streambuf;using streambuf = basic_streambuf<char>;using wstreambuf = basic_streambuf<wchar_t>;}

Class template std::basic_streambuf

namespace std {template<class CharT, class Traits = char_traits<CharT>>class basic_streambuf {public:using char_type = CharT;using int_type =typename Traits::int_type;using pos_type =typename Traits::pos_type;using off_type =typename Traits::off_type;using traits_type = Traits;   virtual ~basic_streambuf();   // locales locale pubimbue(const locale& loc); locale getloc()const;   // buffer and positioning basic_streambuf* 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 and put areas// 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 access 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 access 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// localesvirtualvoid imbue(const locale& loc);   // buffer management and positioningvirtual basic_streambuf* 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);virtualint sync();   // get areavirtual streamsize showmanyc();virtual streamsize xsgetn(char_type* s, streamsize n);virtual int_type underflow();virtual int_type uflow();   // putbackvirtual int_type pbackfail(int_type c = Traits::eof());   // put areavirtual streamsize xsputn(const char_type* s, streamsize n);virtual int_type overflow(int_type c = Traits::eof());};}

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 56	C++98	the return type of showmanyc of was int in the synopsis	corrected to streamsize