[CUDAX] Add in_place_type argument to pass-through constructor of shared resource (#4714)

* Remove direct constructor of shared resource

* Fix the moved resource test

* Switch to inplace_type solution

* Remove leftover pieces of previous solution

Author: pciolkosz

cudax/include/cuda/experimental/__memory_resource/shared_resource.cuh

@@ -26,6 +26,7 @@
 #include <cuda/std/__type_traits/is_swappable.h>
 #include <cuda/std/__utility/exchange.h>
 #include <cuda/std/__utility/forward.h>
+#include <cuda/std/__utility/in_place.h>
 #include <cuda/std/__utility/move.h>
 #include <cuda/std/atomic>
 
@@ -56,7 +57,7 @@ struct shared_resource
   //! dynamically allocated with \c new.
   //! @param __args The arguments to be passed to the \c _Resource constructor.
   template <class... _Args>
-  explicit shared_resource(_Args&&... __args)
+  explicit shared_resource(_CUDA_VSTD::in_place_type_t<_Resource>, _Args&&... __args)
       : __control_block(new _Control_block{_Resource{_CUDA_VSTD::forward<_Args>(__args)...}, 1})
   {}
 
@@ -252,7 +253,7 @@ template <class _Resource, class... _Args>
 auto make_shared_resource(_Args&&... __args) -> shared_resource<_Resource>
 {
   static_assert(_CUDA_VMR::resource<_Resource>, "_Resource does not satisfy the cuda::mr::resource concept");
-  return shared_resource<_Resource>{_CUDA_VSTD::forward<_Args>(__args)...};
+  return shared_resource<_Resource>{_CUDA_VSTD::in_place_type<_Resource>, _CUDA_VSTD::forward<_Args>(__args)...};
 }
 
 } // namespace cuda::experimental

cudax/test/memory_resource/shared_resource.cu

@@ -25,7 +25,7 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
     Counts expected{};
     CHECK(this->counts == expected);
     {
-      cudax::shared_resource<TestResource> mr{42, this};
+      cudax::shared_resource mr{cuda::std::in_place_type<TestResource>, 42, this};
       ++expected.object_count;
       CHECK(this->counts == expected);
     }
@@ -42,7 +42,7 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
     Counts expected{};
     CHECK(this->counts == expected);
     {
-      cudax::shared_resource<TestResource> mr{42, this};
+      cudax::shared_resource mr{cuda::std::in_place_type<TestResource>, 42, this};
       ++expected.object_count;
       CHECK(this->counts == expected);
 
@@ -51,15 +51,20 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
       CHECK(mr == mr2); // pointers compare equal, no call to TestResource::operator==
       CHECK(this->counts == expected);
 
-      auto mr3 = std::move(mr);
+      cudax::shared_resource mr3{mr};
       CHECK(this->counts == expected);
-      CHECK(mr2 == mr3); // pointers compare equal, no call to TestResource::operator==
+      CHECK(mr == mr3); // pointers compare equal, no call to TestResource::operator==
       CHECK(this->counts == expected);
 
-      cudax::shared_resource<TestResource> mr4{TestResource{42, this}};
+      auto mr4 = std::move(mr);
+      CHECK(this->counts == expected);
+      CHECK(mr2 == mr4); // pointers compare equal, no call to TestResource::operator==
+      CHECK(this->counts == expected);
+
+      cudax::shared_resource mr5{cuda::std::in_place_type<TestResource>, TestResource{42, this}};
       ++expected.object_count;
       ++expected.move_count;
-      CHECK(mr3 == mr4); // pointers are not equal, calls TestResource::operator==
+      CHECK(mr4 == mr5); // pointers are not equal, calls TestResource::operator==
       ++expected.equal_to_count;
       CHECK(this->counts == expected);
     }
@@ -76,7 +81,7 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
     Counts expected{};
     CHECK(this->counts == expected);
     {
-      cudax::shared_resource<TestResource> mr{42, this};
+      cudax::shared_resource mr{cuda::std::in_place_type<TestResource>, 42, this};
       ++expected.object_count;
       CHECK(this->counts == expected);
 
@@ -101,7 +106,7 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
   {
     Counts expected{};
     {
-      cudax::shared_resource<TestResource> mr{42, this};
+      cudax::shared_resource mr{cuda::std::in_place_type<TestResource>, 42, this};
       ++expected.object_count;
       CHECK(this->counts == expected);
 
@@ -130,7 +135,7 @@ TEMPLATE_TEST_CASE_METHOD(test_fixture, "shared_resource", "[container][resource
     {
       bytes(42 * sizeof(int));
       cudax::uninitialized_buffer<int, cudax::host_accessible> buffer{
-        cudax::shared_resource<TestResource>(42, this), 42};
+        cudax::shared_resource<TestResource>(cuda::std::in_place_type<TestResource>, 42, this), 42};
       ++expected.object_count;
       ++expected.allocate_count;
       CHECK(this->counts == expected);