SERVER-33909 More detailed error reporting from CAPI

The `libmongodbcapi.h` file now contains detailed documentation of
all preconditions, postconditions, and behaviors.  All operations
now take a `libmongodbcapi_status *` argument which will be
populated with the failure results of an operation.

The internals of how the `libmongodbcapi_` functions are implemented
have been rewritten to catch and report nearly all failures, as well
as to use more native C++ idioms such as exceptions and RAII.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/mongo/logger/log_domain-impl.h b/src/mongo/logger/log_domain-impl.h
index 4d7bef91b58..1ebf5e11f18 100644
--- a/src/mongo/logger/log_domain-impl.h
+++ b/src/mongo/logger/log_domain-impl.h
@@ -81,8 +81,9 @@ template <typename E>
 auto LogDomain<E>::detachAppender(AppenderHandle handle) -> std::unique_ptr<EventAppender> {
     // So technically this could just return a moved unique_ptr reference
     // Still, eliding is a thing so swap is a nice certainty.
-    std::unique_ptr<EventAppender> appender{nullptr};
-    appender.swap(_appenders.at(handle._index));
+    std::unique_ptr<EventAppender> appender;
+    using std::swap;
+    swap(appender, _appenders.at(handle._index));
     return appender;
 }