std::is_error_code_enum<std::io_errc>

 

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

 

Defined in header <ios>
template<> struct is_error_code_enum<std::io_errc>:publicstd::true_type{};		(since C++11)

This specialization of std::is_error_code_enum informs other library components that values of type std::io_errc are enumerations that hold error codes, which makes them implicitly convertible and assignable to objects of type std::error_code.

Inherited from std::integral_constant

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operator bool	converts the object to bool, returns value (public member function)
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Type	Definition
value_type	bool
type	std::integral_constant<bool, value>

Example

The comparison between e.code() and std::io_errc::stream compiles because std::is_error_code_enum<std::io_errc>::value==true.

Run this code

#include <fstream>#include <iostream>   int main(){std::ifstream f("doesn't exist");try{ f.exceptions(f.failbit);}catch(conststd::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

is_error_code_enum (C++11)	identifies a class as an error_code enumeration (class template)
error_code (C++11)	holds a platform-dependent error code (class)
io_errc (C++11)	the IO stream error codes (enum)