Standard library header <ostream>

 

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Concepts library(C++20)

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Filesystem library(C++17)

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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_ostream	wraps a given abstract device (std::basic_streambuf) and provides high-level output interface (class template)
std::ostream	std::basic_ostream<char> (typedef)
std::wostream	std::basic_ostream<wchar_t> (typedef)
Functions
operator<<(std::basic_ostream)	inserts character data or insert into rvalue stream (function template)
print(std::ostream) (C++23)	outputs formatted representation of the arguments (function template)
println(std::ostream) (C++23)	outputs formatted representation of the arguments with appended '\n' (function template)
vprint_unicode(std::ostream) (C++23)	performs Unicode aware output using type-erased argument representation (function)
vprint_nonunicode(std::ostream) (C++23)	outputs character data using type-erased argument representation (function)
Manipulators
endl	outputs '\n' and flushes the output stream (function template)
ends	outputs '\0' (function template)
flush	flushes the output stream (function template)
emit_on_flushnoemit_on_flush (C++20)	controls whether a stream's basic_syncbuf emits on flush (function template)
flush_emit (C++20)	flushes a stream and emits the content if it is using a basic_syncbuf (function template)

Synopsis

namespace std {template<class CharT, class Traits = char_traits<CharT>>class basic_ostream;   using ostream = basic_ostream<char>;using wostream = basic_ostream<wchar_t>;   template<class CharT, class Traits> basic_ostream<CharT, Traits>& endl(basic_ostream<CharT, Traits>& os);template<class CharT, class Traits> basic_ostream<CharT, Traits>& ends(basic_ostream<CharT, Traits>& os);template<class CharT, class Traits> basic_ostream<CharT, Traits>& flush(basic_ostream<CharT, Traits>& os);   template<class CharT, class Traits> basic_ostream<CharT, Traits>& emit_on_flush(basic_ostream<CharT, Traits>& os);template<class CharT, class Traits> basic_ostream<CharT, Traits>& noemit_on_flush(basic_ostream<CharT, Traits>& os);template<class CharT, class Traits> basic_ostream<CharT, Traits>& flush_emit(basic_ostream<CharT, Traits>& os);   template<class Ostream, class T> Ostream&& operator<<(Ostream&& os, const T& x);   // print functionstemplate<class... Args>void print(ostream& os, format_string<Args...> fmt, Args&&... args);template<class... Args>void println(ostream& os, format_string<Args...> fmt, Args&&... args);void println(ostream& os);   void vprint_unicode(ostream& os, string_view fmt, format_args args);void vprint_nonunicode(ostream& os, string_view fmt, format_args args);}

Class template std::basic_ostream

namespace std {template<class CharT, class Traits = char_traits<CharT>>class basic_ostream :virtualpublic basic_ios<CharT, Traits>{public:// types (inherited from basic_ios)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;   // constructor/destructorexplicit basic_ostream(basic_streambuf<char_type, Traits>* sb);virtual ~basic_ostream();   // prefix/suffixclass sentry;   // formatted output basic_ostream& operator<<(basic_ostream&(*pf)(basic_ostream&)); basic_ostream& operator<<(basic_ios<CharT, Traits>&(*pf)(basic_ios<CharT, Traits>&)); basic_ostream& operator<<(ios_base&(*pf)(ios_base&));   basic_ostream& operator<<(bool n); basic_ostream& operator<<(short n); basic_ostream& operator<<(unsignedshort n); basic_ostream& operator<<(int n); basic_ostream& operator<<(unsignedint n); basic_ostream& operator<<(long n); basic_ostream& operator<<(unsignedlong n); basic_ostream& operator<<(longlong n); basic_ostream& operator<<(unsignedlonglong n); basic_ostream& operator<<(float f); basic_ostream& operator<<(double f); basic_ostream& operator<<(longdouble f); basic_ostream& operator<<(/*extended-floating-point-type*/ f);   basic_ostream& operator<<(constvoid* p); basic_ostream& operator<<(constvolatilevoid* p); basic_ostream& operator<<(nullptr_t); basic_ostream& operator<<(basic_streambuf<char_type, Traits>* sb);   // unformatted output basic_ostream& put(char_type c); basic_ostream& write(const char_type* s, streamsize n);   basic_ostream& flush();   // seeks pos_type tellp(); basic_ostream& seekp(pos_type); basic_ostream& seekp(off_type, ios_base::seekdir);   protected:// copy/move constructor basic_ostream(const basic_ostream&)= delete; basic_ostream(basic_ostream&& rhs);   // assignment and swap basic_ostream& operator=(const basic_ostream&)= delete; basic_ostream& operator=(basic_ostream&& rhs);void swap(basic_ostream& rhs);};   // character inserterstemplate<class CharT, class Traits> basic_ostream<CharT, Traits>& operator<<(basic_ostream<CharT, Traits>&, CharT);template<class CharT, class Traits> basic_ostream<CharT, Traits>& operator<<(basic_ostream<CharT, Traits>&, char);template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, char);   template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, signedchar);template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, unsignedchar);   template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, wchar_t)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, char8_t)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, char16_t)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, char32_t)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, char8_t)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, char16_t)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, char32_t)= delete;   template<class CharT, class Traits> basic_ostream<CharT, Traits>& operator<<(basic_ostream<CharT, Traits>&, const CharT*);template<class CharT, class Traits> basic_ostream<CharT, Traits>& operator<<(basic_ostream<CharT, Traits>&, constchar*);template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constchar*);   template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constsignedchar*);template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constunsignedchar*);   template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constwchar_t*)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, const char8_t*)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constchar16_t*)= delete;template<class Traits> basic_ostream<char, Traits>& operator<<(basic_ostream<char, Traits>&, constchar32_t*)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, const char8_t*)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, constchar16_t*)= delete;template<class Traits> basic_ostream<wchar_t, Traits>& operator<<(basic_ostream<wchar_t, Traits>&, constchar32_t*)= delete;}

Class std::basic_ostream::sentry

namespace std {template<class CharT, class Traits>class basic_ostream<CharT, Traits>::sentry{bool ok_;// exposition onlypublic:explicit sentry(basic_ostream& os); ~sentry();explicit operator bool()const{return ok_;}   sentry(const sentry&)= delete; sentry& operator=(const sentry&)= delete;};}