Difference between revisions of "cpp/algorithm/is execution policy"
From cppreference.com
m (nospec) |
m (→Example: added a non-executable example (TBB back-end required).) |
||
| Line 2: | Line 2: | ||
{{cpp/algorithm/navbar}} | {{cpp/algorithm/navbar}} | ||
| − | {{ddcl | header = execution | since=c++17 | 1= | + | {{ddcl|header = execution|since=c++17|1= |
template< class T > | template< class T > | ||
struct is_execution_policy; | struct is_execution_policy; | ||
| Line 9: | Line 9: | ||
Checks whether {{tt|T}} is a standard or implementation-defined execution policy type. | Checks whether {{tt|T}} is a standard or implementation-defined execution policy type. | ||
| − | Provides the member constant {{ | + | Provides the member constant {{c|value}} which is equal to {{c|true}}, if {{tt|T}} is [[cpp/algorithm/execution_policy_tag_t|a standard execution policy type]], or an implementation-defined execution policy type. Otherwise, {{c|value}} is equal to {{c|false}}. |
{{cpp/types/nospec|pv}} | {{cpp/types/nospec|pv}} | ||
| Line 15: | Line 15: | ||
===Template parameters=== | ===Template parameters=== | ||
{{par begin}} | {{par begin}} | ||
| − | {{par | T | a type to check}} | + | {{par|T|a type to check}} |
{{par end}} | {{par end}} | ||
| − | === Helper template === | + | ===Helper template=== |
| − | {{ddcl | header = execution | since=c++17 | 1= | + | {{ddcl|header = execution|since=c++17|1= |
template< class T > | template< class T > | ||
| − | + | constexpr bool is_execution_policy_v = std::is_execution_policy<T>::value; | |
}} | }} | ||
| − | {{cpp/types/integral_constant/inherit | {{tt|T}} is a standard or implementation-defined execution policy type}} | + | {{cpp/types/integral_constant/inherit|{{tt|T}} is a standard or implementation-defined execution policy type}} |
| + | |||
| + | {{example | ||
| + | |code= | ||
| + | #include <execution> | ||
| + | |||
| + | static_assert(std::is_execution_policy_v<std::execution::unsequenced_policy>); | ||
| + | static_assert(!std::is_execution_policy_v<int>); | ||
| + | |||
| + | int main() {} | ||
| + | }} | ||
===See also=== | ===See also=== | ||
{{dsc begin}} | {{dsc begin}} | ||
| − | {{dsc inc | cpp/algorithm/dsc execution_policy_tag_t }} | + | {{dsc inc|cpp/algorithm/dsc execution_policy_tag_t}} |
| − | {{dsc inc | cpp/algorithm/dsc execution_policy_tag }} | + | {{dsc inc|cpp/algorithm/dsc execution_policy_tag}} |
{{dsc end}} | {{dsc end}} | ||
{{langlinks|es|ja|zh}} | {{langlinks|es|ja|zh}} | ||
Latest revision as of 08:26, 24 September 2024
| Defined in header <execution>
|
||
| template< class T > struct is_execution_policy; |
(since C++17) | |
Checks whether T is a standard or implementation-defined execution policy type.
Provides the member constant value which is equal to true, if T is a standard execution policy type, or an implementation-defined execution policy type. Otherwise, value is equal to false.
If the program adds specializations for std::is_execution_policy or std::is_execution_policy_v, the behavior is undefined.
Contents |
[edit] Template parameters
| T | - | a type to check |
[edit] Helper template
| Defined in header <execution>
|
||
| template< class T > constexpr bool is_execution_policy_v = std::is_execution_policy<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if T is a standard or implementation-defined execution policy type, 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 <execution> static_assert(std::is_execution_policy_v<std::execution::unsequenced_policy>); static_assert(!std::is_execution_policy_v<int>); int main() {}
[edit] See also
| (C++17)(C++17)(C++17)(C++20) |
execution policy types (class) |
| (C++17)(C++17)(C++17)(C++20) |
global execution policy objects (constant) |
