[noob question] Parsing offset and size based file

[nenikitov]

Hello! Thank you for the crate.

I'm confused about how can I implement this file type:

#[binrw]
pub struct VfsEntry {
    offset: u32,
    size: u32,
}

#[binrw]
pub struct Vfs {
    #[br(temp)]
    #[bw(try_calc(u32::try_from(_entries.len())))]
    _file_count: u32,

    #[br(temp, count = _file_count)]
    #[bw(/* Not sure here */)]
    _entries: Vec<VfsEntry>,

    // Not sure here
    // entries: Vec<Vec<u8>>
}

There are these 2 examples where the header contains:

• Sizes
• Offsets

But I'm having trouble combining these examples.

How can I create this entries field that contains _file_count entries with the corresponding slice they are pointing to?
Also, how can I generate Vec<VfsEntry> field when writing this file format to binary?

Thank you so much!