introduce OdbcConnection::take

src/connection.rs

@@ -6,7 +6,14 @@ use log::debug;
 use crate::{try_, ArrowOdbcError, ENV};
 
 /// Opaque type to transport connection to an ODBC Datasource over language boundry
-pub struct OdbcConnection(pub Connection<'static>);
+pub struct OdbcConnection(Connection<'static>);
+
+impl OdbcConnection {
+    /// Take the inner connection out of its wrapper
+    pub fn take(self) -> Connection<'static> {
+        self.0
+    }
+}
 
 /// Allocate and open an ODBC connection using the specified connection string. In case of an error
 /// this function returns a NULL pointer.

src/reader.rs

@@ -32,7 +32,7 @@ pub unsafe extern "C" fn arrow_odbc_reader_set_connection(
     connection: NonNull<OdbcConnection>,
 ) {
     let connection = *Box::from_raw(connection.as_ptr());
-    reader.as_mut().set_connection(connection.0);
+    reader.as_mut().set_connection(connection.take());
 }
 
 /// Creates an Arrow ODBC reader instance.

src/writer.rs

@@ -51,7 +51,7 @@ pub unsafe extern "C" fn arrow_odbc_writer_make(
     writer_out: *mut *mut ArrowOdbcWriter,
 ) -> *mut ArrowOdbcError {
     let connection = *Box::from_raw(connection.as_ptr());
-    let connection = connection.0;
+    let connection = connection.take();
 
     let table = slice::from_raw_parts(table_buf, table_len);
     let table = str::from_utf8(table).unwrap();