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fieldoffsets

fieldoffsets(type)

The byte offset of each field of a type relative to the data start. For example, we could use it in the following manner to summarize information about a struct type:

julia> structinfo(T) = [zip(fieldoffsets(T),fieldnames(T),T.types)...];

julia> structinfo(StatStruct)
12-element Array{Tuple{Int64,Symbol,DataType},1}:
 (0,:device,UInt64)
 (8,:inode,UInt64)
 (16,:mode,UInt64)
 (24,:nlink,Int64)
 (32,:uid,UInt64)
 (40,:gid,UInt64)
 (48,:rdev,UInt64)
 (56,:size,Int64)
 (64,:blksize,Int64)
 (72,:blocks,Int64)
 (80,:mtime,Float64)
 (88,:ctime,Float64)

Examples

The fieldoffsets function in Julia returns the byte offset of each field of a given type relative to the data start. Here are some examples of how it can be used:

1. Get field offsets of a struct type:

   julia> struct StatStruct
             device::UInt64
             inode::UInt64
             mode::UInt64
             nlink::Int64
             uid::UInt64
             gid::UInt64
             rdev::UInt64
             size::Int64
             blksize::Int64
             blocks::Int64
             mtime::Float64
             ctime::Float64
          end
   
   julia> fieldoffsets(StatStruct)
   12-element Array{Int64,1}:
   0
   8
   16
   24
   32
   40
   48
   56
   64
   72
   80
   88

   This example shows the byte offset of each field in the StatStruct type.

2. Summarize information about a struct type:

   julia> structinfo(T) = [zip(fieldoffsets(T), fieldnames(T), T.types)...];
   
   julia> structinfo(StatStruct)
   12-element Array{Tuple{Int64, Symbol, DataType},1}:
   (0, :device, UInt64)
   (8, :inode, UInt64)
   (16, :mode, UInt64)
   (24, :nlink, Int64)
   (32, :uid, UInt64)
   (40, :gid, UInt64)
   (48, :rdev, UInt64)
   (56, :size, Int64)
   (64, :blksize, Int64)
   (72, :blocks, Int64)
   (80, :mtime, Float64)
   (88, :ctime, Float64)

   This example defines a structinfo function that summarizes information about a struct type by combining field offsets, field names, and field types.

Please note that the StatStruct type used in the example is for illustration purposes and may not reflect an actual definition.

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