missing bswap function

[stevengj]

It would be nice to be able to convert bigendian data, e.g. SHA hashes as in this discourse thread to UInt256 etcetera, but this currently fails because bswap is not implemented:

julia> h = rand(UInt8, 32);

julia> bytes2hex(h) # interprets h as bigendian
"b9a868cba886baa10e08c841e8c0eabac34b83de68207c8bad6f2c869bc4a547"

julia> reinterpret(UInt256, h) # uses a different byte order
1-element reinterpret(UInt256, ::Vector{UInt8}):
 0x47a5c49b862c6fad8b7c2068de834bc3baeac0e841c8080ea1ba86a8cb68a8b9

julia> ntoh(reinterpret(UInt256, h)) # should convert bigendian to host native order
ERROR: MethodError: no method matching bswap(::Base.ReinterpretArray{UInt256, 1, UInt8, Vector{UInt8}, false})

[rfourquet]

I'm not sure when bswap got implemented, but I assume the error above comes from ntoh not being implemented on arrays, but we can do:

julia> ntoh.(reinterpret(UInt256, h))
1-element Vector{UInt256}:
 0xb9a868cba886baa10e08c841e8c0eabac34b83de68207c8bad6f2c869bc4a547

julia> bswap(reinterpret(UInt256, h)[1])
0xb9a868cba886baa10e08c841e8c0eabac34b83de68207c8bad6f2c869bc4a547

I will close, but please reopen if something is still missing.