Add implicit conversion operators for handcrafted descriptors (#8743)

(cherry picked from commit 52c3561)

Author: flobernd

src/Elastic.Clients.Elasticsearch/_Shared/Helpers/BulkAllRequest.cs

@@ -65,6 +65,8 @@ public sealed class BulkAllRequestDescriptor<T>
 {
 	internal BulkAllRequest<T> Instance { get; }
 
+	public static implicit operator BulkAllRequest<T>(BulkAllRequestDescriptor<T> descriptor) => descriptor.Instance;
+
 	public BulkAllRequestDescriptor(IEnumerable<T> documents)
 	{
 		Instance = new(documents);

src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkCreateOperationDescriptor.cs

@@ -14,6 +14,8 @@ public sealed class BulkCreateOperationDescriptor<TSource> :
 {
 	internal new BulkCreateOperation<TSource> Instance => (BulkCreateOperation<TSource>)base.Instance;
 
+	public static implicit operator BulkCreateOperation<TSource>(BulkCreateOperationDescriptor<TSource> descriptor) => descriptor.Instance;
+
 	public BulkCreateOperationDescriptor(TSource source) :
 		base(new BulkCreateOperation<TSource>(source))
 	{

src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkDeleteOperationDescriptor.cs

@@ -9,6 +9,8 @@ public class BulkDeleteOperationDescriptor :
 {
 	private new BulkDeleteOperation Instance => (BulkDeleteOperation)base.Instance;
 
+	public static implicit operator BulkDeleteOperation(BulkDeleteOperationDescriptor descriptor) => descriptor.Instance;
+
 	public BulkDeleteOperationDescriptor() :
 		base(new BulkDeleteOperation(null!))
 	{
@@ -25,6 +27,8 @@ public sealed class BulkDeleteOperationDescriptor<TDocument> :
 {
 	private new BulkDeleteOperation<TDocument> Instance => (BulkDeleteOperation<TDocument>)base.Instance;
 
+	public static implicit operator BulkDeleteOperation<TDocument>(BulkDeleteOperationDescriptor<TDocument> descriptor) => descriptor.Instance;
+
 	public BulkDeleteOperationDescriptor() :
 		base(new BulkDeleteOperation<TDocument>(null!))
 	{

src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkIndexOperationDescriptor.cs

@@ -14,6 +14,8 @@ public sealed class BulkIndexOperationDescriptor<TSource> :
 {
 	internal new BulkIndexOperation<TSource> Instance => (BulkIndexOperation<TSource>)base.Instance;
 
+	public static implicit operator BulkIndexOperation<TSource>(BulkIndexOperationDescriptor<TSource> descriptor) => descriptor.Instance;
+
 	public BulkIndexOperationDescriptor(TSource source) :
 		base(new BulkIndexOperation<TSource>(source))
 	{

src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkOperationDescriptor.cs

@@ -10,6 +10,8 @@ public abstract class BulkOperationDescriptor<TDescriptor>
 	protected TDescriptor Self => (TDescriptor)this;
 	internal BulkOperation Instance { get; }
 
+	public static implicit operator BulkOperation(BulkOperationDescriptor<TDescriptor> descriptor) => descriptor.Instance;
+
 	internal BulkOperationDescriptor(BulkOperation instance)
 	{
 		Instance = instance;

src/Elastic.Clients.Elasticsearch/_Shared/Types/Core/Bulk/BulkUpdateOperationDescriptor.cs

@@ -13,6 +13,8 @@ public sealed class BulkUpdateOperationDescriptor<TDocument, TPartialDocument> :
 {
 	internal new BulkUpdateOperation<TDocument, TPartialDocument> Instance => (BulkUpdateOperation<TDocument, TPartialDocument>)base.Instance;
 
+	public static implicit operator BulkUpdateOperation<TDocument, TPartialDocument>(BulkUpdateOperationDescriptor<TDocument, TPartialDocument> descriptor) => descriptor.Instance;
+
 	public BulkUpdateOperationDescriptor() :
 		base(new BulkUpdateOperation<TDocument, TPartialDocument>(null!))
 	{