Add possibility for VectorView to be a temporary

Author: Vladimir Dimic

include/graphblas/base/vector.hpp

@@ -875,7 +875,7 @@ namespace grb {
 			}
 };
 
-	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C >
+	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C, typename tmp >
 	class VectorView { };
 
 }

include/graphblas/denseref/vector.hpp

@@ -209,19 +209,19 @@ namespace grb {
 	 * Here starts spec draft for vectorView
 	 */
 
-	template< typename T, typename View, typename C >
-	size_t getLength( const VectorView< T, View, storage::Dense, reference_dense, C > &v ) noexcept {
+	template< typename T, typename View, typename C, typename tmp >
+	size_t getLength( const VectorView< T, View, storage::Dense, reference_dense, C, tmp > &v ) noexcept {
 		return v._length();
 	}
 
 	/**
 	 * Identity View over a vector container.
 	 */
-	template< typename T, typename C >
-	class VectorView< T, view::Identity< void >, storage::Dense, reference_dense, C > {
+	template< typename T, typename C, typename tmp >
+	class VectorView< T, view::Identity< void >, storage::Dense, reference_dense, C, tmp > {
 
 	private:
-		using self_type = VectorView< T, view::Identity< void >, storage::Dense, reference_dense, C >;
+		using self_type = VectorView< T, view::Identity< void >, storage::Dense, reference_dense, C, tmp >;
 
 		/*********************
 		    Storage info friends
@@ -249,25 +249,31 @@ namespace grb {
 		/** @see Vector::value_type. */
 		using value_type = T;
 
+		/**
+		 * @brief Any vector view type which allocates a physical container provides a version of 
+		 * itself for defining a temporary vector of the same type via the \a tmp_t member type.
+		 */
+		using tmp_t = VectorView< T, view::Identity< void >, storage::Dense, reference_dense, C, true >;
+
 		VectorView( const size_t length ) : v( std::make_unique< Vector< T, reference_dense, C > >( length ) ), imf( std::make_shared< imf::Id >( length ) ), initialized( false ) {}
 
 	}; // class VectorView with physical container
 
 	/** Identifies any reference_dense vector as an ALP vector. */
-	template< typename T, typename View, typename Storage, typename C >
-	struct is_container< VectorView< T, View, Storage, reference_dense, C > > {
+	template< typename T, typename View, typename Storage, typename C, typename tmp >
+	struct is_container< VectorView< T, View, Storage, reference_dense, C, tmp > > {
 		/** A reference_vector is an ALP object. */
 		static const constexpr bool value = true;
 	};
 
 	/**
 	 * Vector view of a vector only via \a view::Identity of another VectorView.
 	 */
-	template< typename T, typename VectorViewT, typename C >
-	class VectorView< T, view::Identity< VectorViewT >, storage::Dense, reference_dense, C > {
+	template< typename T, typename VectorViewT, typename C, typename tmp >
+	class VectorView< T, view::Identity< VectorViewT >, storage::Dense, reference_dense, C, tmp > {
 
 	private:
-		using self_type = VectorView< T, view::Identity< VectorViewT >, storage::Dense, reference_dense, C >;
+		using self_type = VectorView< T, view::Identity< VectorViewT >, storage::Dense, reference_dense, C, tmp >;
 		using target_type = VectorViewT;
 
 		/*********************
@@ -311,13 +317,13 @@ namespace grb {
 	/**
 	 * Diagonal Vector View of a structured matrix.
 	 */
-	template< typename T, typename StructuredMatrixT, typename C >
-	class VectorView< T, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C > {
+	template< typename T, typename StructuredMatrixT, typename C, typename tmp >
+	class VectorView< T, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C, tmp > {
 
 	private:
 		/** Exposes the own type and the type of the VectorView object over
 		 * which this view is created. */
-		using self_type = VectorView< T, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C >;
+		using self_type = VectorView< T, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C, tmp >;
 		using target_type = StructuredMatrixT;
 
 		/*********************
@@ -359,11 +365,11 @@ namespace grb {
 	 * 
 	 * @returns                     A VectorView object.
 	 * */
-	template< typename StructuredMatrixT, typename C = internal::DefaultCoordinates >
-	VectorView< typename StructuredMatrixT::value_type, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C >
+	template< typename StructuredMatrixT, typename C = internal::DefaultCoordinates, typename tmp = false >
+	VectorView< typename StructuredMatrixT::value_type, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C, tmp >
 	diagonal( StructuredMatrixT &smat ) {
 
-		VectorView< typename StructuredMatrixT::value_type, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C > smat_diag( smat );
+		VectorView< typename StructuredMatrixT::value_type, view::Diagonal< StructuredMatrixT >, storage::Dense, reference_dense, C, tmp > smat_diag( smat );
 
 		return smat_diag;
 	}
@@ -375,11 +381,11 @@ namespace grb {
 	 * 
 	 * @returns          A VectorView object.
 	 */
-	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C = internal::DefaultCoordinates >
-	VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C > 
-	get_view( VectorView< T, View, StorageSchemeType, backend, C > &source ) {
+	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C = internal::DefaultCoordinates, typename tmp = false >
+	VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C, tmp > 
+	get_view( VectorView< T, View, StorageSchemeType, backend, C, tmp > &source ) {
 
-		VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C > vec_view( source );
+		VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C, tmp > vec_view( source );
 
 		return vec_view;
 	}
@@ -394,11 +400,11 @@ namespace grb {
 	 * @returns          A VectorView object.
 	 */
 
-	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C >
-	VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C > 
-	get_view( VectorView< T, View, StorageSchemeType, backend, C > &source, std::shared_ptr< imf::IMF > imf ) {
+	template< typename T, typename View, typename StorageSchemeType, enum Backend backend, typename C, typename tmp = false >
+	VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C, tmp > 
+	get_view( VectorView< T, View, StorageSchemeType, backend, C, tmp > &source, std::shared_ptr< imf::IMF > imf ) {
 
-		VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C > vec_view( source, imf );
+		VectorView< T, view::Identity< VectorView< T, View, StorageSchemeType, backend, C > >, StorageSchemeType, backend, C, tmp > vec_view( source, imf );
 
 		return vec_view;
 	}

include/graphblas/vector.hpp

@@ -50,7 +50,7 @@ namespace grb {
 	/*
 	 * The default value of \a StorageSchemeType could also be made conditional (Dense or Sparse) depending on \a config::default_backend
 	 */
-	template< typename T, typename View = view::Identity< void >, typename StorageSchemeType = storage::Dense, enum Backend backend = config::default_backend, typename C = internal::DefaultCoordinates >
+	template< typename T, typename View = view::Identity< void >, typename StorageSchemeType = storage::Dense, enum Backend backend = config::default_backend, typename C = internal::DefaultCoordinates, bool tmp = false >
 	class VectorView;
 
 }