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 2025-03-14 UTC."],[[["The webpage provides a list of available versions for `google::cloud::pubsub::PullResponse`, ranging from version 2.11.0 up to the latest release candidate 2.37.0-rc."],["Each version listed links to the documentation for `structgoogle_1_1cloud_1_1pubsub_1_1PullResponse` specific to that release."],["The content describes how `handler.ack()` or `handler.nack()` are used to acknowledge or negatively acknowledge a message, affecting redelivery behavior."],["The page notes that behavior can differ between \"exactly-once delivery\" and \"best-efforts\" subscriptions regarding message redelivery even after successful `handler.ack()`."],["The document points out that `std::move` might be needed when using `handler.ack()` or `handler.nack()` if the `handler` isn't an rvalue."]]],[]]
