std::is_error_code_enum<std::io_errc>
From cppreference.com
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.
Contents |
Inherited from std::integral_constant
Member constants
value
[static]
|
true (public static member constant) |
Member functions
operator bool |
converts the object to bool, returns value (public member function) |
Member types
Type | Definition |
value_type
|
bool
|
type
|
std::integral_constant<bool, value> |
[edit] 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 <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
[edit] See also
(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) |