How do I check if a byte in the instruction is a relocatable data?

[stevefan1999-personal]

I want to replicate https://github.com/senator715/IDA-Fusion in Iced for signature scanning but I cannot figure out how to do that in Iced. In IDA there is some function that indicates whether the byte at the currently scanned position is a relocation data, I'm not sure if iced has the same.