Defined in header <ios> | ||
---|---|---|
template< > struct is_error_code_enum<std::io_errc> : public std::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
.
value
[static] | true (public static member constant) |
operator bool | converts the object to bool , returns value (public member function) |
operator()
(C++14) | returns value (public member function) |
Type | Definition |
---|---|
value_type | bool |
type | std::integral_constant<bool, value> |
The comparison between e.code()
and std::io_errc::stream
compiles because std::is_error_code_enum<std::io_errc>::value == true
.
#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
(C++11) | identifies a class as an error_code enumeration (class template) |
(C++11) | holds a platform-dependent error code (class) |
(C++11) | the IO stream error codes (enum) |
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