what in particular are you having

what in particular are you having trouble with?
F# has

ref T

ref T

ref T

ref T via

byref<'T>

byref<'T>

byref<'T>

byref<'T>,

in T

in T

in T

in T via

inref<'T>

inref<'T>

inref<'T>

inref<'T>,

out T

out T

out T

out T via

outref<'T>

outref<'T>

outref<'T>

outref<'T>
you can declare pointers via

nativeptr<'T>

nativeptr<'T>

nativeptr<'T>

nativeptr<'T>

and for external functions in particular (

DllImport

DllImport

DllImport

DllImport) it directly supports

T*

T*

T*

T* and

T&

T&

T&

T& for pointers/byrefs