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 latest version available is 2.37.0-rc, with links provided for documentation for each version, starting from 2.37.0-rc down to version 2.11.0."],["The content describes the `PullResponse` for a blocking pull, highlighting that the service will redeliver the message if `handler.nack()` is called or if the handler goes out of scope."],["For exactly-once delivery subscriptions, messages are no longer redelivered after a successful `handler.ack()`, while best-effort subscriptions may still redeliver messages even after a successful acknowledgment."],["When `handler` is not an rvalue, the user might need to call `std::move(handler).ack()` or `std::move(handler).nack()`."]]],[]]
