std::is_error_code_enum
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> |
#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) |
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