you can’t do computation within type parameters, Julia does NOT have dependent types; here’s a hack:
julia> for M = 0:10
@eval f(x::MVector{$M,T}) where {T} = "less than 10"
end
julia> f(@MVector [1,2,3,4,5,6,7,8,9,10,11])
"This is the fallback generic function"
julia> f(@MVector [1,2,3,4,5,6,7,8,9])
"less than 10"