std::is_error_code_enum
From cppreference.com
< cpp | error | error code
| Defined in header <system_error>
|
||
| template< class T > struct is_error_code_enum; |
(since C++11) | |
If T is an error code enumeration (such as std::io_errc and std::future_errc), this template provides the member constant value equal true. For any other type, value is false.
This template may be specialized for a program-defined type to indicate that the type is eligible for std::error_code implicit conversion.
Helper variable template
| template< class T > constexpr bool is_error_code_enum_v = is_error_code_enum<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if T is an error code enum, false otherwise (public static member constant) |
Member functions
| operator bool |
converts the object to bool, returns value (public member function) |
| operator() (C++14) |
returns value (public member function) |
Member types
| Type | Definition |
value_type
|
bool |
type
|
std::integral_constant<bool, value> |
Run this code
#include <ios> #include <system_error> static_assert(std::is_error_code_enum_v<decltype(std::io_errc::stream)>); static_assert(!std::is_error_code_enum_v<std::error_category>); int main() {}
See also
| (C++11) |
identifies an enumeration as an std::error_condition (class template) |