feat(float): add of_string_opt

src/core/CCFloat.ml

@@ -112,6 +112,9 @@ let of_int (a:int) = Stdlib.float_of_int a
 let to_string (a:float) = Stdlib.string_of_float a
 let of_string_exn (a:string) = Stdlib.float_of_string a
 let of_string (a:string) = Stdlib.float_of_string a
+let of_string_opt (a:string) =
+  try Some (Stdlib.float_of_string a)
+  with _ -> None
 
 
 let random n st = Random.State.float st n

src/core/CCFloat.mli

@@ -104,6 +104,9 @@ val of_string : string -> t
     @raise Failure in case of failure. *)
 [@@ocaml.deprecated "use of_string_exn instead"]
 
+val of_string_opt : string -> t option
+(** @since NEXT_RELEASE *)
+
 val equal_precision : epsilon:t -> t -> t -> bool
 (** Equality with allowed error up to a non negative epsilon value. *)