use enable_if to allow using containers of interfaces with object wra…

…ppers (#683)

* check container of interfaces move constructor and direct initialization

* use enable_if in interface constructor

* test elements of moved container of interfaces

* bring back allowed types comment

python/templates/Interface.h.jinja2

@@ -92,10 +92,10 @@ private:
  std::unique_ptr<Concept> m_self{nullptr};
 
 public:
-  template<typename ValueT>
+  // {{ class.bare_type }} can only be initialized with one of the following types (and their Mutable counter parts): {{ Types | join(", ") }}
+  template<typename ValueT, typename = std::enable_if_t<isInitializableFrom<ValueT>>>
   {{ class.bare_type }}(ValueT value) :
     m_self(std::make_unique<Model<podio::detail::GetDefaultHandleType<ValueT>>>(value)) {
-    static_assert(isInitializableFrom<ValueT>, "{{ class.bare_type }} can only be initialized with one of the following types (and their Mutable counter parts): {{ Types | join(", ") }}");
   }
 
   {{ class.bare_type }}(const {{ class.bare_type }}& other) :

tests/unittests/interface_types.cpp

@@ -1,14 +1,18 @@
 #include "catch2/catch_test_macros.hpp"
 
+#include "datamodel/ExampleHit.h"
 #include "datamodel/ExampleHitCollection.h"
 #include "datamodel/MutableExampleCluster.h"
+#include "datamodel/MutableExampleMC.h"
 #include "datamodel/TypeWithEnergy.h"
 
 #include "podio/ObjectID.h"
 #include "podio/utilities/TypeHelpers.h"
 
 #include <map>
 #include <stdexcept>
+#include <utility>
+#include <vector>
 
 TEST_CASE("InterfaceTypes basic functionality", "[interface-types][basics]") {
   using WrapperT = TypeWithEnergy;
@@ -67,6 +71,16 @@ TEST_CASE("InterfaceTypes STL usage", "[interface-types][basics]") {
   REQUIRE(counterMap[empty] == 1);
   REQUIRE(counterMap[hit] == 2);
   REQUIRE(counterMap[wrapper] == 2);
+
+  auto mc = MutableExampleMC{};
+  mc.energy() = 3.14f;
+
+  // check container of interfaces move constructor and direct initialization
+  auto interfaces = std::vector<TypeWithEnergy>{empty, hit, mc};
+  auto interfaces2 = std::vector<TypeWithEnergy>{std::move(interfaces)};
+  REQUIRE_FALSE(interfaces2.at(0).isAvailable());
+  REQUIRE(interfaces2.at(1).isA<ExampleHit>());
+  REQUIRE(interfaces2.at(2).energy() == 3.14f);
 }
 
 TEST_CASE("InterfaceType from immutable", "[interface-types][basics]") {