std::io_errc

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

Input/output library

I/O manipulators

C-style I/O

Buffers

basic_streambuf

basic_filebuf

basic_stringbuf

strstreambuf (deprecated)

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

istrstream (deprecated)

ostrstream (deprecated)

strstream (deprecated)

Synchronized Output

basic_osyncstream (C++20)

Types

streamoff

streamsize

fpos

Error category interface

iostream_category (C++11)

io_errc (C++11)

std::io_errc

Non-member functions

make_error_code(std::io_errc)

make_error_condition(std::io_errc)

Helper classes

is_error_code_enum<std::io_errc>

Defined in header <ios>
enum class io_errc { stream = 1, };		(since C++11)

The scoped enumeration std::io_errc defines the error codes reported by I/O streams in std::ios_base::failure exception objects. Only one error code (std::io_errc::stream) is required, although the implementation may define additional error codes. Because the appropriate specialization of std::is_error_code_enum is provided, values of type std::io_errc are implicitly convertible to std::error_code.

Member constants

Enumeration constant	Value
stream	1

Non-member functions

make_error_code(std::io_errc) (C++11)	constructs an iostream error code (function)
make_error_condition(std::io_errc) (C++11)	constructs an iostream error_condition (function)

Helper classes

is_error_code_enum<std::io_errc> (C++11)

extends the type trait std::is_error_code_enum to identify iostream error codes (class template)

Example

Run this code

#include <iostream>
#include <fstream>
int main()
{
    std::ifstream f("doesn't exist");
    try {
        f.exceptions(f.failbit);
    } catch (const std::ios_base::failure& e) {
        std::cout << "Caught an ios_base::failure.\n";
        if(e.code() == std::io_errc::stream)
            std::cout << "The error code is std::io_errc::stream\n";
    }
}

Output:

Caught an ios_base::failure.
The error code is std::io_errc::stream

See also

error_code (C++11)	holds a platform-dependent error code (class)
error_condition (C++11)	holds a portable error code (class)
failure	stream exception (public member class of std::ios_base)