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."],[[["The webpage provides a list of available versions for `PullResponse` in the Google Cloud Pub/Sub C++ library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc."],["Each listed version number links to the corresponding documentation for `structgoogle_1_1cloud_1_1pubsub_1_1PullResponse`."],["The `PullResponse` documentation covers the response behavior for blocking pulls, including how messages are redelivered based on whether the handler invokes `ack()` or `nack()`."],["The content explains that exactly-once delivery subscriptions stop message redelivery after a successful `handler.ack()` call, whereas best-effort subscriptions may still redeliver messages in certain circumstances."],["It also contains a note that if the handler isn't an rvalue then the user may need to utilize `std::move(handler).ack()` or `std::move(handler).nack()`."]]],[]]
