Remove construct_cell, too experimental

The API hasn't received enough thought. It's isn't
ready for release. If useful this can be added
later.

Author: ranfdev

glib-macros/tests/properties.rs

@@ -7,7 +7,6 @@ fn props() {
     mod foo {
         use glib::prelude::*;
         use glib::subclass::prelude::*;
-        use glib::{ConstructCell, ConstructRefCell};
         use glib_macros::Properties;
         use std::cell::Cell;
         use std::cell::RefCell;
@@ -86,10 +85,6 @@ fn props() {
                 once_cell: OnceCell<u8>,
                 #[property(get, set)]
                 cell: Cell<u8>,
-                #[property(get, set)]
-                construct_cell: ConstructCell<u8>,
-                #[property(get, set)]
-                construct_ref_cell: ConstructRefCell<u8>,
             }
 
             impl ObjectImpl for Foo {
@@ -102,10 +97,6 @@ fn props() {
                 fn property(&self, id: usize, _pspec: &ParamSpec) -> Value {
                     Self::derived_property(self, id, _pspec)
                 }
-                fn constructed(&self) {
-                    self.construct_cell.replace(Some(1));
-                    self.construct_ref_cell.replace(Some(2));
-                }
             }
 
             #[glib::object_subclass]
@@ -222,13 +213,6 @@ fn props() {
         // member of struct field
         let author_nick = myfoo.author_nick();
         assert_eq!(author_nick, myfoo.property::<String>("author-nick"));
-
-        // construct_cell
-        let n = myfoo.construct_cell();
-        assert_eq!(n, myfoo.property::<u8>("construct-cell"));
-
-        let n = myfoo.construct_ref_cell();
-        assert_eq!(n, myfoo.property::<u8>("construct-ref-cell"));
     }
 
     // setters

glib/src/construct_cell.rs

@@ -127,8 +127,6 @@ mod byte_array;
 mod bytes;
 pub mod char;
 pub use self::char::*;
-mod construct_cell;
-pub use construct_cell::*;
 mod checksum;
 pub mod closure;
 mod convert;