[ https://issues.apache.org/jira/browse/ARROW-486?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Wes McKinney resolved ARROW-486. -------------------------------- Resolution: Fixed Issue resolved by pull request 282 [https://github.com/apache/arrow/pull/282] > [C++] arrow::io::MemoryMappedFile can't be casted to arrow::io::FileInterface > ----------------------------------------------------------------------------- > > Key: ARROW-486 > URL: https://issues.apache.org/jira/browse/ARROW-486 > Project: Apache Arrow > Issue Type: Bug > Components: C++ > Affects Versions: 0.2.0 > Environment: Linux > Reporter: Kouhei Sutou > > arrow::io::ReadWriteFileInterface inheritances arrow::io::FileInterface > as diamond style via: > * ReadableFileInterface -> InputStream -> FileInterface > * WriteableFileInterface -> OutputStream -> FileInterface > If we have diamond inheritance, we can't cast subclasses of > arrow::io::ReadWriteFileInterface such as arrow::io::MemoryMappedFile to > arrow::io::FileInterface. > C++: > #include <arrow/io/file.h> > int > main(void) > { > std::shared_ptr<arrow::io::MemoryMappedFile> memory_mapped_file; > std::shared_ptr<arrow::io::FileInterface> file = memory_mapped_file; > return 0; > } > Build result: > a.cc: In function 'int main()': > a.cc:8:52: error: conversion from > 'std::shared_ptr<arrow::io::MemoryMappedFile>' to non-scalar type > 'std::shared_ptr<arrow::io::FileInterface>' requested > std::shared_ptr<arrow::io::FileInterface> file = memory_mapped_file; > ^~~~~~~~~~~~~~~~~~ > We can resolve it by using virtual inheritance. -- This message was sent by Atlassian JIRA (v6.3.4#6332)