### execution::executor_index

The `execution::executor_index` trait detects the type used by an executor to represent an index within a bulk operation.

    template<
        typename T>
    struct executor_index

##### Types

Name | Description
--- | ---
type | T::index_type if T::index_type is valid, otherwise executor_shape_t<T>.

Class template `executor_index` is a type trait with a nested type alias `type` whose type is `T::index_type` if `T::index_type` is valid, otherwise `executor_shape_t<T>`.

##### Requirements

Header: `asio/execution/executor.hpp`

Convenience header: `asio/execution.hpp`