Remove scary lifetime-of-rows-may-panic from README.

Closes #119.
This commit is contained in:
John Gallagher
2016-02-01 14:30:51 -05:00
parent 4149389318
commit a793f8c8c5
2 changed files with 4 additions and 46 deletions

View File

@@ -983,6 +983,9 @@ pub type SqliteRows<'stmt> = Rows<'stmt>;
///
/// ## Warning
///
/// Strongly consider using `query_map` or `query_and_then` instead of `query`; the former do not
/// suffer from the following problem.
///
/// Due to the way SQLite returns result rows of a query, it is not safe to attempt to get values
/// from a row after it has become stale (i.e., `next()` has been called again on the `Rows`
/// iterator). For example:
@@ -994,7 +997,7 @@ pub type SqliteRows<'stmt> = Rows<'stmt>;
/// let mut rows = try!(stmt.query(&[]));
///
/// let row0 = try!(rows.next().unwrap());
/// // row 0 is value now...
/// // row 0 is valid for now...
///
/// let row1 = try!(rows.next().unwrap());
/// // row 0 is now STALE, and row 1 is valid
@@ -1008,12 +1011,6 @@ pub type SqliteRows<'stmt> = Rows<'stmt>;
/// (which would result in a collection of rows, only the last of which can safely be used) and
/// `min`/`max` (which could return a stale row unless the last row happened to be the min or max,
/// respectively).
///
/// This problem could be solved by changing the signature of `next` to tie the lifetime of the
/// returned row to the lifetime of (a mutable reference to) the result rows handle, but this would
/// no longer implement `Iterator`, and therefore you would lose access to the majority of
/// functions which are useful (such as support for `for ... in ...` looping, `map`, `filter`,
/// etc.).
pub struct Rows<'stmt> {
stmt: &'stmt Statement<'stmt>,
current_row: Rc<Cell<c_int>>,