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 2025-04-17 UTC."],[[["The webpage provides documentation for various versions of the `PullResponse` structure in the Google Cloud Pub/Sub C++ library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc."],["The `PullResponse` structure is used to handle the response from a blocking pull operation in Pub/Sub."],["The message redelivery behavior depends on whether the subscription is configured for exactly-once delivery or best-efforts delivery, as exactly-once subscriptions stop redelivery upon successful acknowledgment, while best-efforts subscriptions may still redeliver."],["Acknowledging or negatively acknowledging a message is done via `handler.ack()` or `handler.nack()` respectively, and if `handler` is not an rvalue then `std::move(handler).ack()` or `std::move(handler).nack()` may be needed."],["The webpage is giving documentation related to the struct `google::cloud::pubsub::PullResponse` which pertains to the Google Cloud Pub/Sub C++ library."]]],[]]
