add shim create_index implementation

Author: amidvidy

src/mongocxx/collection.cpp

@@ -402,6 +402,22 @@ std::int64_t collection::count(bsoncxx::document::view filter, const options::co
     return result;
 }
 
+bsoncxx::document::value collection::create_index(bsoncxx::document::view keys, bsoncxx::document::view options) {
+    scoped_bson_t bson_keys{keys};
+    bson_error_t error;
+
+    auto result = libmongoc::collection_create_index(_impl->collection_t, bson_keys.bson(),
+                                                     nullptr, &error);
+
+    if (!result) {
+        // TODO: throw an exception here
+    }
+
+    // TODO: return the response from the server, this is not possible now due to the way
+    // libmongoc works.
+    return bsoncxx::document::value{bsoncxx::document::view{}};
+}
+
 void collection::drop() {
     bson_error_t error;
 

src/mongocxx/collection.hpp

@@ -199,7 +199,7 @@ class LIBMONGOCXX_API collection {
     /// @param options
     ///   Optional arguments to index creation command, see ensureindex-options link
     ///
-    /// @throws operation_exception if the aggregation fails.
+    /// @throws operation_exception if index creation fails.
     ///
     /// @see http://docs.mongodb.org/manual/reference/method/db.collection.createIndex/
     /// @see http://docs.mongodb.org/manual/reference/method/db.collection.ensureIndex/#ensureindex-options

src/mongocxx/private/libmongoc_symbols.hpp

@@ -36,6 +36,7 @@ MONGOCXX_LIBMONGOC_SYMBOL(client_get_collection)
 MONGOCXX_LIBMONGOC_SYMBOL(client_destroy)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_aggregate)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_count)
+MONGOCXX_LIBMONGOC_SYMBOL(collection_create_index)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_destroy)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_set_read_prefs)
 MONGOCXX_LIBMONGOC_SYMBOL(collection_get_read_prefs)