const IndexHeader = struct
const IndexHeader = struct { fan_out_table: [256]u32, const signature = "\xFFtOc"; const supported_version = 2; const size = 4 + 4 + @sizeOf([256]u32); fn read(index_header: *IndexHeader, reader: *Io.Reader) !void { const sig = try reader.take(4); if (!mem.eql(u8, sig, signature)) return error.InvalidHeader; const version = try reader.takeInt(u32, .big); if (version != supported_version) return error.UnsupportedVersion; try reader.readSliceEndian(u32, &index_header.fan_out_table, .big); } }