openpgp: Implement FromStr for some types.

  - This implements std::str::FromStr for types that have
    string-representations and are reasonably likely to be encountered
    by downstream users, e.g. fingerprints or messages.  This allows
    us to do `"xxx".parse()?`.

  - Fixes #320.

1 files changed, 8 insertions, 0 deletions

diff --git a/openpgp/src/crypto/keygrip.rs b/openpgp/src/crypto/keygrip.rs
index 9bf4bf5b..66240b92 100644
--- a/openpgp/src/crypto/keygrip.rs
+++ b/openpgp/src/crypto/keygrip.rs
@@ -29,6 +29,14 @@ impl fmt::Display for Keygrip {
     }
 }
 
+impl std::str::FromStr for Keygrip {
+    type Err = failure::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_hex(s)
+    }
+}
+
 impl Keygrip {
     /// Parses a keygrip.
     pub fn from_hex(hex: &str) -> Result<Self> {