std::basic_ostream<CharT,Traits>::write

From cppreference.com

Compiler support
Freestanding and hosted
Language
Standard library
Standard library headers
Named requirements
Feature test macros(C++20)
Language support library
Concepts library(C++20)
Diagnostics library
Memory management library
Metaprogramming library(C++11)
General utilities library
Containers library
Iterators library
Ranges library(C++20)
Algorithms library
Strings library
Text processing library
Numerics library
Date and time library
Input/output library
Filesystem library(C++17)
Concurrency support library(C++11)
Execution control library(C++26)
Technical specifications
Symbols index
External libraries

[edit]

Input/output library

I/O manipulators
Print functions(C++23)
C-style I/O
Buffers
basic_streambuf
basic_filebuf
basic_stringbuf
basic_spanbuf (C++23)
strstreambuf (C++98/26*)
basic_syncbuf (C++20)
Streams
Abstractions
ios_base
basic_ios
basic_istream
basic_ostream
basic_iostream
File I/O
basic_ifstream
basic_ofstream
basic_fstream
String I/O
basic_istringstream
basic_ostringstream
basic_stringstream
Array I/O
basic_ispanstream (C++23)
basic_ospanstream (C++23)
basic_spanstream (C++23)
istrstream (C++98/26*)
ostrstream (C++98/26*)
strstream (C++98/26*)
Synchronized Output
basic_osyncstream (C++20)
Types
streamoff
streamsize
fpos
Error category interface
iostream_category (C++11)
io_errc (C++11)

Global objects

Member functions

basic_ostream::basic_ostream

basic_ostream::~basic_ostream

basic_ostream::operator=

(C++11)

Formatted output

basic_ostream::operator<<

Unformatted output

basic_ostream::put

basic_ostream::write

Positioning

Miscellaneous

(C++11)

Member classes

basic_ostream::sentry

Non-member functions

operator<<(std::basic_ostream)

print(std::ostream)

(C++23)

println(std::ostream)

(C++23)

vprint_unicode(std::ostream)

(C++23)

vprint_nonunicode(std::ostream)

(C++23)

[edit]

basic_ostream& write(const char_type* s,std::streamsize count);

Behaves as anUnformattedOutputFunction. After constructing and checking the sentry object, outputs the characters from successive locations in the character array whose first element is pointed to bys. Characters are inserted into the output sequence until one of the following occurs:

exactlycount characters are inserted
inserting into the output sequence fails (in which casesetstate(badbit) is called).

[edit]Parameters

s	-	pointer to the character string to write
count	-	number of characters to write

[edit]Return value

*this

[edit]Exceptions

[edit]

failure if an error occurred (the error state flag is notgoodbit) andexceptions() is set to throw for that state.

If an internal operation throws an exception, it is caught andbadbit is set. Ifexceptions() is set forbadbit, the exception is rethrown.

[edit]Notes

This function is not overloaded for the typessignedchar orunsignedchar, unlike the formattedoperator<<.

Also, unlike the formatted output functions, this function does not set thefailbit on failure.

When using a non-converting locale (the default locale is non-converting), the overrider of this function instd::basic_ofstream may be optimized for zero-copy bulk I/O (by means of overridingstd::streambuf::xsputn).

[edit]Example

This function may be used to output object representations, i.e. binary output

Run this code

#include <iostream> int main(){int n=0x41424344;std::cout.write(reinterpret_cast<char*>(&n), sizeof n)<<'\n'; char c[]="This is sample text.";std::cout.write(c,4).write("!\n",2);}

Possible output:

DCBAThis!

[edit]See also

operator<<(std::basic_ostream)	inserts character data or insert into rvalue stream (function template)[edit]
put	inserts a character (public member function)[edit]