# Specifying type of interpolated image in a struct

I have a struct

``````struct some_struct{}
interpolated_img
end
``````

where I want to store an interpolation ‘image’. When I print the `typeof()` such an image, I get `Interpolations.BSplineInterpolation{Gray{Float64}, 2, Matrix{Gray{Float64}}, BSpline{Linear{Throw{OnGrid}}}, Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}}}` .

If I don’t specify any type, it assumes it as `Any`, but if I want to specify the type should I specify it as something like
`interpolated_img::Interpolations.BSplineInterpolation{Gray{Float64}, 2, Matrix{Gray{Float64}}, BSpline{Linear{Throw{OnGrid}}}, Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}}}`
or is there some better way to do this?

You can add a type parameter that will be filled in when compiled.

``````struct some_struct{T}
interpolated_img::T
end
``````

Perfect, thank you!