Obtain an executor with the default allocator property.

constexpr basic_executor_type< std::allocator< void >, Bits > require(
    execution::allocator_t< void > ) const;

Do not call this function directly. It is intended for use with the require customisation point.

For example:

auto ex1 = my_thread_pool.executor();
auto ex2 = asio::require(ex1,
    asio::execution::allocator);