cpp: Add some convenience functions

* lang/cpp/src/context.cpp (Context::create): New.
* lang/cpp/src/context.h: Update accordingly.
* lang/cpp/src/key.cpp, lang/cpp/src/key.h:
(Key::isBad, Subkey::isBad, UserID::isBad)
(UserID::Signature::isBad): Add shorthand for the isX checks.
* NEWS: Mention it.

--
I don't know how often I wrote:
if (key.isNull() || key.isExpired() || key.isRevoked() ...

And for the context it is good practice to use a unique ptr
so the API should make it easy.

1 files changed, 5 insertions, 0 deletions

diff --git a/lang/cpp/src/context.cpp b/lang/cpp/src/context.cpp
index 2892d8b4..ce38db0b 100644
--- a/lang/cpp/src/context.cpp
+++ b/lang/cpp/src/context.cpp
@@ -228,6 +228,11 @@ Context *Context::createForProtocol(Protocol proto)
     return new Context(ctx);
 }
 
+std::unique_ptr<Context> Context::create(Protocol proto)
+{
+  return std::unique_ptr <Context> (createForProtocol(proto));
+}
+
 std::unique_ptr<Context> Context::createForEngine(Engine eng, Error *error)
 {
     gpgme_ctx_t ctx = 0;