openpgp: Pass a timestamp to the KeyIter instead of each filter.

  - KeyIter::revoked and KeyIter::key_flags (and its variants) didn't
    take a time stamp so they could only be used for filtering keys
    based on their current state, not their state at some time in the
    past.  Adding a time stamp to each of the filters would have fixed
    the problem, but it would have made the interface ugly: callers
    always want the same time stamp for all filters.

  - Split KeyIter into two structures: a KeyIter and a ValidKeyIter.

  - Add KeyIter::policy.  It takes a time stamp, which is then used
    for filters like `alive` and `revoked`, and it returns a
    ValidKeyIter, which exposes filters that require a time stamp.

1 files changed, 2 insertions, 2 deletions

diff --git a/openpgp/src/serialize/cert.rs b/openpgp/src/serialize/cert.rs
index 773606a6..4c217cbf 100644
--- a/openpgp/src/serialize/cert.rs
+++ b/openpgp/src/serialize/cert.rs
@@ -316,7 +316,7 @@ impl<'a> TSK<'a> {
     /// # f().unwrap();
     /// # fn f() -> Result<()> {
     /// let (cert, _) = CertBuilder::new().add_signing_subkey().generate()?;
-    /// assert_eq!(cert.keys().alive().revoked(false).secret().count(), 2);
+    /// assert_eq!(cert.keys().policy(None).alive().revoked(false).secret().count(), 2);
     ///
     /// // Only write out the primary key's secret.
     /// let mut buf = Vec::new();
@@ -328,7 +328,7 @@ impl<'a> TSK<'a> {
     ///     .serialize(&mut buf)?;
     ///
     /// let cert_ = Cert::from_bytes(&buf)?;
-    /// assert_eq!(cert_.keys().alive().revoked(false).secret().count(), 1);
+    /// assert_eq!(cert_.keys().policy(None).alive().revoked(false).secret().count(), 1);
     /// assert!(cert_.primary().secret().is_some());
     /// # Ok(()) }
     pub fn set_filter<P>(mut self, predicate: P) -> Self