Support for a drop-in replacement of std::fstream class in C++

[gigony]

This feature request aligns with Python's counterparts and is being mentioned here for reference:

• Add seek and tell to Python CuFile object #576
• Consider subclassing Python CuFile object from io.RawIOBase #577

In addition to the POSIX API (pread/pwrite) for unbuffered I/O, many C++ projects utilize std::fstream for loading file content. Although std::fstream is intended for buffered I/O, I believe there are numerous use cases where kvikio could be seamlessly integrated into C++ projects by replacing std::fstream with kvikio's corresponding class.

Reference:

• https://en.cppreference.com/w/cpp/io/basic_fstream

We could also explore the possibility of subclassing the following classes:

• https://en.cppreference.com/w/cpp/io/ios_base
• https://en.cppreference.com/w/cpp/header/spanstream (for array I/O implementations introduced in C++23)

cc: @jakirkham

[jakirkham]

Thanks Gigon! 🙏

Think this is a good writeup on how we might make KvikIO usage more idiomatic for C++ users

@jrhemstad as someone who has thought a lot about how to improve C++ users' CUDA experience, would be interested to hear your thoughts on what API would be best for us to present for file operations

[jakirkham]

Looks like a similar discussion came up in the context of CCCL: NVIDIA/cccl#3359