#nowarn "0042"
let inline retype (x: 'T) : 'U = (# "" x: 'U #)

open System
type Curry =

    static member inline Invoke f =
        let inline call_2 (a: ^a, b: ^b) = ((^a or ^b) : (static member Curry: _*_ -> _) b, a)
        call_2 (Unchecked.defaultof<Curry>, Unchecked.defaultof<'t>) (f: 't -> 'r) : 'args

    static member inline Curry (t: 't, _: Curry) = fun f t1 t2 t3 t4 t5 t6 t7 ->
        Curry.Invoke (fun tr ->
            let (t1: 't1) = if false then (^t : (member Item1 : 't1) t) else t1
            let (t2: 't2) = if false then (^t : (member Item2 : 't2) t) else t2
            let (t3: 't3) = if false then (^t : (member Item3 : 't3) t) else t3
            let (t4: 't4) = if false then (^t : (member Item4 : 't4) t) else t4
            let (t5: 't5) = if false then (^t : (member Item5 : 't5) t) else t5
            let (t6: 't6) = if false then (^t : (member Item6 : 't6) t) else t6
            let (t7: 't7) = if false then (^t : (member Item7 : 't7) t) else t7
            let (tr: 'tr) = if false then (^t : (member Rest  : 'tr) t) else tr
            f (Tuple<_,_,_,_,_,_,_,_>(t1, t2, t3, t4, t5, t6, t7, tr) |> retype))

    static member Curry (x: Tuple<'t1>               , _: Curry) = fun f t1                   -> f (Tuple<_> t1)
    static member Curry ((t1, t2)                    , _: Curry) = fun f t1 t2                -> f (t1, t2)
    static member Curry ((t1, t2, t3)                , _: Curry) = fun f t1 t2 t3             -> f (t1, t2, t3)
    static member Curry ((t1, t2, t3, t4)            , _: Curry) = fun f t1 t2 t3 t4          -> f (t1, t2, t3, t4)
    static member Curry ((t1, t2, t3, t4, t5)        , _: Curry) = fun f t1 t2 t3 t4 t5       -> f (t1, t2, t3, t4, t5)
    static member Curry ((t1, t2, t3, t4, t5, t6)    , _: Curry) = fun f t1 t2 t3 t4 t5 t6    -> f (t1, t2, t3, t4, t5, t6)
    static member Curry ((t1, t2, t3, t4, t5, t6, t7), _: Curry) = fun f t1 t2 t3 t4 t5 t6 t7 -> f (t1, t2, t3, t4, t5, t6, t7)

let inline curry f t = Curry.Invoke f t


///////////
// TESTS //
///////////

let f2 (x, y)    = [x + y]
let f3 (x, y, z) = [x + y + z]
let f7 (t1, t2, t3, t4, t5, t6, t7) = [t1+t2+t3+t4+t5+t6+t7]
let f8 (t1, t2, t3, t4, t5, t6, t7: float, t8: char) = [t1+t2+t3+t4+t5+t6+ int t7 + int t8]
let f9  (t1, t2, t3, t4, t5, t6, t7: float, t8: char, t9: decimal) = [t1+t2+t3+t4+t5+t6+ int t7 + int t8+ int t9]
let f15 (t1, t2, t3, t4, t5, t6, t7: float, t8: char, t9: decimal, t10, t11, t12, t13, t14, t15) = [t1+t2+t3+t4+t5+t6+ int t7 + int t8+ int t9+t10+t11+t12+t13+t14+t15]
let f16 (t1, t2, t3, t4, t5, t6, t7: float, t8: char, t9: decimal, t10, t11, t12, t13, t14, t15, t16) = [t1+t2+t3+t4+t5+t6+ int t7 + int t8+ int t9+t10+t11+t12+t13+t14+t15+t16]
let f17 (t1, t2, t3, t4, t5, t6, t7: float, t8: char, t9: decimal, t10, t11, t12, t13, t14, t15, t16, t17) = [t1+t2+t3+t4+t5+t6+ int t7 + int t8+ int t9+t10+t11+t12+t13+t14+t15+t16+t17]
let f1 (x:Tuple<_>) = [x.Item1]

let x2 = curry f2 1 2
let x3 = curry f3 1 2 3
let x7 = curry f7 1 2 3 4 5 6 7
let x8 = curry f8 1 2 3 4 5 6 7. '8'
let x9 = curry f9 1 2 3 4 5 6 7. '8' 9M
let x15 = curry f15 1 2 3 4 5 6 7. '8' 9M 10 11 12 13 14 15
let x16 = curry f16 1 2 3 4 5 6 7. '8' 9M 10 11 12 13 14 15 16
let x17 = curry f17 1 2 3 4 5 6 7. '8' 9M 10 11 12 13 14 15 16 17
let x1 = curry f1 100