Use std::mem::take instead of std::mem::replace, for clarity

Replace

    let bar = std::mem::replace(&foo, Default::Default());

with

    let bar = std::mem::take(&foo);

The new version seems a little clearer. Found by clippy:
https://rust-lang.github.io/rust-clippy/master/index.html#mem_replace_with_default

Sponsored-by: author

2 files changed, 2 insertions, 3 deletions

diff --git a/openpgp/src/cert/parser/mod.rs b/openpgp/src/cert/parser/mod.rs
index d5f9b5e7..02516428 100644
--- a/openpgp/src/cert/parser/mod.rs
+++ b/openpgp/src/cert/parser/mod.rs
@@ -783,7 +783,7 @@ impl<'a> CertParser<'a> {
     // Returns the old state.  Note: the packet iterator is preserved.
     fn reset(&mut self) -> Self {
         // We need to preserve `source` and `filter`.
-        let mut orig = mem::replace(self, Default::default());
+        let mut orig = mem::take(self);
         self.source = orig.source.take();
         mem::swap(&mut self.filter, &mut orig.filter);
         orig
diff --git a/openpgp/src/parse/hashed_reader.rs b/openpgp/src/parse/hashed_reader.rs
index 7dc02a65..f4ee5964 100644
--- a/openpgp/src/parse/hashed_reader.rs
+++ b/openpgp/src/parse/hashed_reader.rs
@@ -370,8 +370,7 @@ pub(crate) fn hash_buffered_reader<R>(reader: R,
     reader.drop_eof()?;
 
     let hashes =
-        mem::replace(&mut reader.cookie_mut().sig_group_mut().hashes,
-                     Default::default());
+        mem::take(&mut reader.cookie_mut().sig_group_mut().hashes);
     Ok(hashes)
 }