If the application invokes handler.nack() or allows handler to go out of scope, then the service will redeliver the message.
With exactly-once delivery subscriptions, the service will stop redelivering the message once the application invokes handler.ack() and the invocation succeeds. With best-efforts subscriptions, the service may redeliver the message, even after a successful handler.ack() invocation.
If handler is not an rvalue, you may need to use std::move(handler).ack() or std::move(handler).nack().
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-03-21 UTC."],[[["This webpage provides access to the C++ Pub/Sub library documentation for various versions, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The documentation specifically references the `PullResponse` struct within the `google::cloud::pubsub` namespace, across each version."],["The content details how the message will be redelivered if the application invokes `handler.nack()` or allows `handler` to go out of scope."],["With exactly-once delivery subscriptions, the message stops being redelivered after a successful `handler.ack()`, while best-effort subscriptions might still redeliver the message even after acknowledgment."],["The content provides a link to the exact-once delivery subscription documentation for more information: \u003chttps://cloud.google.com/pubsub/docs/exactly-once-delivery\u003e."]]],[]]
