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This is a traits class to identify whether a particular type is an error condition enum type, and thus can be used to construct or assign values to objects of type error_condition.
This header provides a default definition, which simply inherits from false_type, and a specialization for errc, which inherits from true_type. Custom error condition enum types should specialize it as inheriting from true_type in order to be used to construct error_condition objects. The standard error condition types io_errc and future_errc inherit true_type.
Reference
C library:
- <cassert> (assert.h)
- <cctype> (ctype.h)
- <cerrno> (errno.h)
-
<cfenv> (fenv.h)C++11
- <cfloat> (float.h)
-
<cinttypes> (inttypes.h)C++11
- <ciso646> (iso646.h)
- <climits> (limits.h)
- <clocale> (locale.h)
- <cmath> (math.h)
- <csetjmp> (setjmp.h)
- <csignal> (signal.h)
- <cstdarg> (stdarg.h)
-
<cstdbool> (stdbool.h)C++11
- <cstddef> (stddef.h)
-
<cstdint> (stdint.h)C++11
- <cstdio> (stdio.h)
- <cstdlib> (stdlib.h)
- <cstring> (string.h)
-
<ctgmath> (tgmath.h)C++11
- <ctime> (time.h)
-
<cuchar> (uchar.h)C++11
- <cwchar> (wchar.h)
- <cwctype> (wctype.h)
Containers:
-
<array>C++11
- <deque>
-
<forward_list>C++11
- <list>
- <map>
- <queue>
- <set>
- <stack>
-
<unordered_map>C++11
-
<unordered_set>C++11
- <vector>
-
Input/Output:
Multi-threading:
-
<atomic>C++11
-
<condition_variable>C++11
-
<future>C++11
-
<mutex>C++11
-
<thread>C++11
-
Other:
- <algorithm>
- <bitset>
-
<chrono>C++11
-
<codecvt>C++11
- <complex>
- <exception>
- <functional>
-
<initializer_list>C++11
- <iterator>
- <limits>
- <locale>
- <memory>
- <new>
- <numeric>
-
<random>C++11
-
<ratio>C++11
-
<regex>C++11
- <stdexcept>
- <string>
-
<system_error>C++11
-
<tuple>C++11
-
<type_traits>C++11
-
<typeindex>C++11
- <typeinfo>
- <utility>
- <valarray>
<system_error>
classes
-
error_categoryC++11
-
error_codeC++11
-
error_conditionC++11
-
is_error_code_enumC++11
-
is_error_condition_enumC++11
-
system_errorC++11
-
enum classes
-
errcC++11
-
functions
-
generic_categoryC++11
-
make_error_codeC++11
-
make_error_conditionC++11
-
system_categoryC++11
-
- Reference
- <system_error>
- is_error_condition_enum
class
<system_error>
std::is_error_condition_enum
template <class T>struct is_error_condition_enum : public false_type {};template<>struct is_error_condition_enum<errc> : true_type {};error_condition enum flag
- integral_constant
- is_error_condition_enum
This is a traits class to identify whether a particular type is an error condition enum type, and thus can be used to construct or assign values to objects of type error_condition.
This header provides a default definition, which simply inherits from false_type, and a specialization for errc, which inherits from true_type. Custom error condition enum types should specialize it as inheriting from true_type in order to be used to construct error_condition objects. The standard error condition types io_errc and future_errc inherit true_type.
Template parameters
Member types
Inherited from integral_constant (is_false and is_true are typedefs of integral_constant instantiations):| member type | definition |
|---|---|
| value_type | bool |
| type | either true_type or false_type |
Member constants
Inherited from integral_constant (is_false and is_true are typedefs of integral_constant instantiations):| member constant | definition |
|---|---|
| value | either true or false |
Member functions
Inherited from integral_constant (is_false and is_true are typedefs of integral_constant instantiations):- operator bool
- Returns value (public member function)
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Spotted an error? contact us