tag of a variant and record type difference

[Kuba Roth]

Hello,
I don't quite understand the following error and was wondering what is the correct approach for pattern matching. I'd like to be able to to match a type and have a custom printer.
As far as i understand the T1 {x;} tag of a variant t2 is of the same t1 type. Why (in pattern matching) once "m" is matched with T1 I'm still not able to pass it to pprint function?
Thank you.

Error: This expression has type t2 but an expression was expected of type t1

type t1 = {
    x : int;
};;

type t2 =
    | T1 of t1
    | B of int
    | C of float;;
    
    
let a = {x=4};;
let b = T1 {x=4};;

let pprint m =
   print_int m.x;;


let pprintB m =
    match m with
    | T1 {x;} -> pprint m            (*  errors on m *)
    | _ -> print_string " exit "

[Kuba Roth]

ahhh.... found the issue:

let pprintB m =
    match m with

    | T1 m -> pprint m
    | _ -> print_string " exit "

[Malcolm Matalka]

T1 r is not the same type, it wraps a value of t1.  So:

T1 t1 -> pprint t1

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