Question 1

How do I map a file with an existing file descriptor using mio?

Accepted Answer

Pass the file descriptor to the constructor or map function, but note that mio doesn't check permissions, so ensure the descriptor has correct access rights. Use error codes to handle potential mapping failures.

Question 2

mio vs Boost.Iostreams for memory mapping in C++?

Accepted Answer

mio is lighter, header-only, and has no dependencies, with better support for file handles and automatic page alignment. Boost.Iostreams offers more features but comes with overhead and less flexibility for specific use cases.

Question 3

Can I use mio in a project with exceptions disabled?

Accepted Answer

Yes, by using the factory functions like make_mmap_source or the map member function with error codes, as constructors require exceptions. This allows integration in -fno-exceptions builds.

Question 4

How to flush changes to disk after writing with mio?

Accepted Answer

Call the sync() method on the mapping object to explicitly flush changes, or rely on the destructor to automatically sync and unmap when the object goes out of scope, ensuring data persistence.

Question 5

Does mio support wide character paths on Windows?

Accepted Answer

Yes, the library supports wide character types for path parameters on Windows, as mentioned in the README, making it compatible with Unicode file paths.

Question 6

What's the difference between mmap_source and mmap_sink in mio?

Accepted Answer

mmap_source is for read-only mappings, while mmap_sink is for read-write mappings. Choose based on whether you need to modify the file content directly in memory.

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