Change cudf::scalar copy and move constructors to protected

cpp/include/cudf/scalar/scalar.hpp

@@ -45,23 +45,10 @@ namespace cudf {
  */
 class scalar {
  public:
-  virtual ~scalar()      = default;
-  scalar(scalar&& other) = default;
-
+  virtual ~scalar() = default;
   scalar& operator=(scalar const& other) = delete;
   scalar& operator=(scalar&& other) = delete;
 
-  /**
-   * @brief Construct a new scalar object by deep copying another.
-   *
-   * @param other The scalar to copy.
-   * @param stream CUDA stream used for device memory operations.
-   * @param mr Device memory resource to use for device memory allocation.
-   */
-  scalar(scalar const& other,
-         rmm::cuda_stream_view stream        = rmm::cuda_stream_default,
-         rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
-
   /**
    * @brief Returns the scalar's logical value type.
    */
@@ -103,6 +90,19 @@ class scalar {
 
   scalar() = delete;
 
+  scalar(scalar&& other) = default;
+
+  /**
+   * @brief Construct a new scalar object by deep copying another.
+   *
+   * @param other The scalar to copy.
+   * @param stream CUDA stream used for device memory operations.
+   * @param mr Device memory resource to use for device memory allocation.
+   */
+  scalar(scalar const& other,
+         rmm::cuda_stream_view stream        = rmm::cuda_stream_default,
+         rmm::mr::device_memory_resource* mr = rmm::mr::get_current_device_resource());
+
   /**
    * @brief Construct a new scalar object.
    *

cpp/tests/binaryop/binop-fixture.hpp

@@ -74,7 +74,7 @@ struct BinaryOperationTest : public cudf::test::BaseFixture {
     cudf::test::UniformRandomGenerator<uint8_t> rand_gen(r_min, r_max);
     uint8_t size = rand_gen.generate();
     std::string str{"ஔⒶbc⁂∰ൠ \tنж水✉♪✿™"};
-    return cudf::scalar_type_t<T>(string_view(str.data(), size));
+    return cudf::scalar_type_t<T>(str.substr(0, size));
   }
 };