API: remove UniqueResult, lower-case at, size for ResultSet

include/caosdb/transaction.h

@@ -34,7 +34,6 @@
 #include <iterator>
 // IWYU pragma: no_include <ext/alloc_traits.h>
 #include <memory> // for shared_ptr, unique_ptr
-#include <stdexcept>
 #include <string> // for string
 #include <vector> // for vector
 
@@ -179,8 +178,9 @@ class ResultSet {
 
 public:
   virtual ~ResultSet() = default;
-  [[nodiscard]] virtual auto Size() const noexcept -> int = 0;
-  [[nodiscard]] virtual auto At(const int index) const -> const Entity & = 0;
+  [[nodiscard]] virtual auto size() const noexcept -> int = 0;
+  [[nodiscard]] virtual auto at(const int index) const -> const Entity & = 0;
+  [[nodiscard]] virtual auto mutable_at(int index) const -> Entity * = 0;
   auto begin() const -> iterator;
   auto end() const -> iterator;
 
@@ -201,49 +201,22 @@ private:
 
 /**
  * Container with results of a transaction.
- *
- * In contrast to UniqueResult, this one can also hold multiple entities or zero
- * entities.
  */
 class MultiResultSet : public ResultSet {
 public:
   ~MultiResultSet() = default;
   explicit MultiResultSet(std::vector<std::unique_ptr<Entity>> result_set);
-  [[nodiscard]] inline auto Size() const noexcept -> int override {
+  [[nodiscard]] inline auto size() const noexcept -> int override {
     return this->entities.size();
   }
-  [[nodiscard]] inline auto At(const int index) const
+  [[nodiscard]] inline auto at(const int index) const
     -> const Entity & override {
     return *(this->entities.at(index));
   }
-  std::vector<std::unique_ptr<Entity>> entities;
-};
-
-/**
- * Container with the single result of a transaction.
- *
- * In contrast to MultiResultSet, this one guarantees to hold exactly one
- * entity.
- */
-class UniqueResult : public ResultSet {
-public:
-  ~UniqueResult() = default;
-  explicit inline UniqueResult(ProtoEntity *protoEntity)
-    : entity(new Entity(protoEntity)){};
-  explicit inline UniqueResult(IdResponse *idResponse)
-    : entity(new Entity(idResponse)){};
-  [[nodiscard]] auto GetEntity() const -> const Entity &;
-  [[nodiscard]] inline auto Size() const noexcept -> int override { return 1; }
-  [[nodiscard]] inline auto At(const int index) const
-    -> const Entity & override {
-    if (index != 0) {
-      throw std::out_of_range("Index out of range. Length is 1.");
-    }
-    return *(this->entity);
+  [[nodiscard]] inline auto mutable_at(int index) const -> Entity * override {
+    return this->entities.at(index).get();
   }
-
-private:
-  std::unique_ptr<Entity> entity;
+  std::vector<std::unique_ptr<Entity>> entities;
 };
 
 /**