start to hack the innards

src/sys/table_collection.rs

@@ -14,4 +14,12 @@ impl TableCollection {
         tsk.as_mut().sequence_length = sequence_length;
         Self(tsk)
     }
+
+    pub fn as_ptr(&self) -> *const tsk_table_collection_t {
+        self.0.as_ptr()
+    }
+
+    pub fn as_mut_ptr(&self) -> *mut tsk_table_collection_t {
+        self.0.as_mut_ptr()
+    }
 }

src/table_collection.rs

@@ -3,6 +3,7 @@ use std::vec;
 
 use crate::error::TskitError;
 use crate::sys::bindings as ll_bindings;
+use crate::sys::TableCollection as LLTableCollection;
 use crate::types::Bookmark;
 use crate::IndividualTableSortOptions;
 use crate::Position;
@@ -54,18 +55,11 @@ use mbox::MBox;
 /// ```
 ///
 pub struct TableCollection {
-    inner: MBox<ll_bindings::tsk_table_collection_t>,
+    inner: LLTableCollection,
     idmap: Vec<NodeId>,
     views: crate::table_views::TableViews,
 }
 
-impl Drop for TableCollection {
-    fn drop(&mut self) {
-        let rv = unsafe { tsk_table_collection_free(self.as_mut_ptr()) };
-        assert_eq!(rv, 0);
-    }
-}
-
 /// Returns a pointer to an uninitialized tsk_table_collection_t
 pub(crate) fn uninit_table_collection() -> MBox<ll_bindings::tsk_table_collection_t> {
     let temp = unsafe {
@@ -101,26 +95,12 @@ impl TableCollection {
                 expected: "sequence_length >= 0.0".to_string(),
             });
         }
-        let mut mbox = uninit_table_collection();
-        let rv = unsafe { ll_bindings::tsk_table_collection_init(&mut *mbox, 0) };
-        if rv < 0 {
-            return Err(crate::error::TskitError::ErrorCode { code: rv });
-        }
-        let views = crate::table_views::TableViews::new_from_mbox_table_collection(&mut mbox)?;
-        // AHA?
-        assert!(std::ptr::eq(
-            &mbox.as_ref().edges as *const ll_bindings::tsk_edge_table_t,
-            views.edges().as_ref() as *const ll_bindings::tsk_edge_table_t
-        ));
-        let mut tables = Self {
-            inner: mbox,
+        let inner = LLTableCollection::new(sequence_length.into());
+        Ok(Self{
+            inner,
             idmap: vec![],
-            views,
-        };
-        unsafe {
-            (*tables.as_mut_ptr()).sequence_length = f64::from(sequence_length);
-        }
-        Ok(tables)
+            view: TableViews:
+        })
     }
 
     /// # Safety
@@ -1279,11 +1259,11 @@ impl TableCollection {
 
     /// Pointer to the low-level C type.
     pub fn as_ptr(&self) -> *const ll_bindings::tsk_table_collection_t {
-        &*self.inner
+        self.inner.as_ptr()
     }
 
     /// Mutable pointer to the low-level C type.
     pub fn as_mut_ptr(&mut self) -> *mut ll_bindings::tsk_table_collection_t {
-        &mut *self.inner
+        self.inner.as_mut_ptr()
     }
 }