QFuture: extend the docs to explain how to cancel continuation chain

Task-number: QTBUG-97582
Change-Id: Ib31d0dfb7a74bb88802a21c5875edd789e412529
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/corelib/doc/snippets/code/src_corelib_thread_qfuture.cpp b/src/corelib/doc/snippets/code/src_corelib_thread_qfuture.cpp
index f4278abcbc..b8a4e708a5 100644
--- a/src/corelib/doc/snippets/code/src_corelib_thread_qfuture.cpp
+++ b/src/corelib/doc/snippets/code/src_corelib_thread_qfuture.cpp
@@ -294,3 +294,20 @@ auto continuation = future.then(context, [] (Results results) {
     // May or may not run in the context's thread
 });
 //! [20]
+
+//! [21]
+QFuture<int> testFuture = ...;
+auto resultFuture = testFuture.then([](int res) {
+    // Block 1
+    ...
+    return 1;
+}).then([](int res) {
+    // Block 2
+    ...
+    return 2;
+}).onCanceled([] {
+    // Block 3
+    ...
+    return -1;
+});
+//! [21]