[py] replace deprecated placement new for custom ctors

python/dune/xt/la/container/matrix-interface.hh

@@ -42,10 +42,9 @@ struct addbind_Matrix
     namespace py = pybind11;
     using namespace pybind11::literals;
 
-    c.def("__init__",
-          [](T& self, const ssize_t rows, const ssize_t cols, const S& value) {
-            new (&self) T(Common::numeric_cast<size_t>(rows), Common::numeric_cast<size_t>(cols), value);
-          },
+    c.def(py::init([](const ssize_t rows, const ssize_t cols, const S& value) {
+            return new T(Common::numeric_cast<size_t>(rows), Common::numeric_cast<size_t>(cols), value);
+          }),
           "rows"_a = 0,
           "cols"_a = 0,
           "value"_a = 0.0);
@@ -100,10 +99,9 @@ typename std::enable_if<is_matrix<C>::value, pybind11::class_<C>>::type bind_Mat
   addbind_ProvidesBackend(c);
 
   internal::addbind_Matrix<C, sparse>::template ctor<S>(c);
-  c.def("__init__",
-        [](C& self, const ssize_t rows, const ssize_t cols, const SparsityPatternDefault& pattern) {
-          new (&self) C(Common::numeric_cast<size_t>(rows), Common::numeric_cast<size_t>(cols), pattern);
-        },
+  c.def(py::init([](const ssize_t rows, const ssize_t cols, const SparsityPatternDefault& pattern) {
+          return new C(Common::numeric_cast<size_t>(rows), Common::numeric_cast<size_t>(cols), pattern);
+        }),
         "rows"_a,
         "cols"_a,
         "pattern"_a);

python/dune/xt/la/container/pattern.hh

@@ -35,10 +35,9 @@ pybind11::class_<SparsityPatternDefault> bind_SparsityPatternDefault(pybind11::m
 
   py::class_<SparsityPatternDefault> c(m, "SparsityPatternDefault", "SparsityPatternDefault");
 
-  c.def("__init__",
-        [](C& self, const ssize_t size) {
+  c.def(py::init([](const ssize_t size) {
           try {
-            new (&self) C(boost::numeric_cast<size_t>(size));
+            return new C(boost::numeric_cast<size_t>(size));
           } catch (boost::bad_numeric_cast& ee) {
             DUNE_THROW(Common::Exceptions::wrong_input_given,
                        "Given size has to be positive!\n\n The error in boost while converting '"
@@ -48,7 +47,7 @@ pybind11::class_<SparsityPatternDefault> bind_SparsityPatternDefault(pybind11::m
                            << "' was: "
                            << ee.what());
           }
-        },
+        }),
         "size"_a = 0);
 
   c.def("insert", &C::insert, "outer_index"_a, "inner_index"_a);

python/dune/xt/la/container/vector-interface.hh

@@ -46,22 +46,15 @@ typename std::enable_if<is_vector<C>::value, pybind11::class_<C>>::type bind_Vec
   py::class_<C> c = bind_ProvidesDataAccess<C>(m, ClassName, ClassName);
   addbind_ProvidesBackend(c);
 
-  c.def("__init__",
-        [](C& vec, const ssize_t size, const S& value) { new (&vec) C(Common::numeric_cast<size_t>(size), value); },
+  c.def(py::init([](const ssize_t size, const S& value) { return new C(Common::numeric_cast<size_t>(size), value); }),
         "size"_a = 0,
         "value"_a = 0.0);
-  c.def("__init__",
-        [](C& vec, py::iterable it) {
+  c.def(py::init([](py::iterable it) {
           std::vector<S> tmp;
-          try {
-            for (py::handle h : it)
-              tmp.push_back(h.cast<S>());
-            new (&vec) C(tmp);
-          } catch (...) {
-            vec.~C();
-            throw;
-          }
-        },
+          for (py::handle h : it)
+            tmp.push_back(h.cast<S>());
+          return new C(tmp);
+        }),
         "Assigns the elements of the iterable to the vector.");
 
   c.def("__repr__",