add default create for sketch classes

Author: cflint

core/sketch/count_sketch.cpp

@@ -50,6 +50,15 @@ CountSketch<ValueType, IndexType>::create(
 }
 
 
+template <typename ValueType, typename IndexType>
+std::unique_ptr<CountSketch<ValueType, IndexType>>
+CountSketch<ValueType, IndexType>::create(
+    std::shared_ptr<const Executor> exec)
+{
+    return std::unique_ptr<CountSketch>{new CountSketch(exec)};
+}
+
+
 template <typename ValueType, typename IndexType>
 void CountSketch<ValueType, IndexType>::apply_sketch_impl(
     const matrix::Dense<ValueType>* b, matrix::Dense<ValueType>* x) const

core/sketch/gaussian_sketch.cpp

@@ -51,6 +51,15 @@ std::unique_ptr<GaussianSketch<ValueType>> GaussianSketch<ValueType>::create(
 }
 
 
+
+template <typename ValueType>
+std::unique_ptr<GaussianSketch<ValueType>> GaussianSketch<ValueType>::create(
+    std::shared_ptr<const Executor> exec)
+{
+    return std::unique_ptr<GaussianSketch>{new GaussianSketch(exec)};
+}
+
+
 template <typename ValueType>
 void GaussianSketch<ValueType>::apply_sketch_impl(
     const matrix::Dense<ValueType>* b, matrix::Dense<ValueType>* x) const

core/sketch/sparse_stack.cpp

@@ -51,6 +51,13 @@ SparseStack<ValueType, IndexType>::create(std::shared_ptr<const Executor> exec,
         new SparseStack(exec, sketch_size, input_size, zeta, seed)};
 }
 
+template <typename ValueType, typename IndexType>
+std::unique_ptr<SparseStack<ValueType, IndexType>>
+SparseStack<ValueType, IndexType>::create(std::shared_ptr<const Executor> exec)
+{
+    return std::unique_ptr<SparseStack>{new SparseStack(exec)};
+}
+
 
 template <typename ValueType, typename IndexType>
 void SparseStack<ValueType, IndexType>::apply_sketch_impl(

include/ginkgo/core/sketch/count_sketch.hpp

@@ -53,6 +53,14 @@ class CountSketch
         std::shared_ptr<const Executor> exec, size_type sketch_size,
         size_type input_size, uint64 seed);
 
+    /**
+     * Creates an uninitialized CountSketch operator.
+     *
+     * @param exec  executor where the sketch lives
+     */
+    static std::unique_ptr<CountSketch> create(
+        std::shared_ptr<const Executor> exec);
+
     /** Returns the random seed. */
     uint64 get_seed() const { return seed_; }
 

include/ginkgo/core/sketch/gaussian_sketch.hpp

@@ -52,6 +52,14 @@ class GaussianSketch
         std::shared_ptr<const Executor> exec, size_type sketch_size,
         size_type input_size, uint64 seed);
 
+    /**
+     * Creates an uninitialized GaussianSketch operator.
+     *
+     * @param exec  executor where the sketch lives
+     */
+    static std::unique_ptr<GaussianSketch> create(
+        std::shared_ptr<const Executor> exec);
+
     /** Returns the random seed used to generate this sketch. */
     uint64 get_seed() const { return seed_; }
 

include/ginkgo/core/sketch/sparse_stack.hpp

@@ -53,6 +53,13 @@ class SparseStack : public EnableLinOp<SparseStack<ValueType, IndexType>,
     static std::unique_ptr<SparseStack> create(
         std::shared_ptr<const Executor> exec, size_type sketch_size,
         size_type input_size, size_type zeta, uint64 seed);
+    
+    /**
+     * Creates an uninitialized SparseStack operator.
+     *
+     * @param exec  executor where the sketch lives
+     */
+    static std::unique_ptr<SparseStack> create(std::shared_ptr<const Executor> exec);
 
     /** Returns the random seed. */
     uint64 get_seed() const { return seed_; }