lynshi opened a new pull request, #39755: URL: https://github.com/apache/arrow/pull/39755
The [current `MapBuilder` documentation](https://arrow.apache.org/docs/cpp/api/builder.html#_CPPv4N5arrow10MapBuilderE) says: > To use this class, you must append values to the key and item array builders and use the Append function to delimit each distinct map (once the keys and items have been appended) This contradicts the [docstring for `Append`](https://arrow.apache.org/docs/cpp/api/builder.html#_CPPv4N5arrow10MapBuilder6AppendEv): > This function should be called before beginning to append elements to the key and item builders The `Append` documentation is correct; it should be called *before* keys and items have been appended. If `Append` is called after, as the `MapBuilder` docstring suggests, `Finish` results in an empty `Array`. ### What changes are included in this PR? Documentation only change. <!-- There is no need to duplicate the description in the issue here but it is sometimes worth providing a summary of the individual changes in this PR. --> ### Are these changes tested? There are no behavior changes. <!-- We typically require tests for all PRs in order to: 1. Prevent the code from being accidentally broken by subsequent changes 2. Serve as another way to document the expected behavior of the code If tests are not included in your PR, please explain why (for example, are they covered by existing tests)? --> ### Are there any user-facing changes? No <!-- If there are user-facing changes then we may require documentation to be updated before approving the PR. --> <!-- If there are any breaking changes to public APIs, please uncomment the line below and explain which changes are breaking. --> <!-- **This PR includes breaking changes to public APIs.** --> <!-- Please uncomment the line below (and provide explanation) if the changes fix either (a) a security vulnerability, (b) a bug that caused incorrect or invalid data to be produced, or (c) a bug that causes a crash (even when the API contract is upheld). We use this to highlight fixes to issues that may affect users without their knowledge. For this reason, fixing bugs that cause errors don't count, since those are usually obvious. --> <!-- **This PR contains a "Critical Fix".** --> -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
