ArrayView: added constructors to initialize const views by const references

src/TNL/Containers/ArrayView.h

@@ -62,6 +62,16 @@ public:
    __cuda_callable__
    ArrayView( StaticArray< Size, Element_ >& array );
 
+   // these constructors will be used only when Element is const-qualified
+   // (const views are initializable by const references)
+   template< typename Element_ >  // template catches both const and non-const qualified Element
+   __cuda_callable__
+   ArrayView( const Array< Element_, Device, Index >& array );
+
+   template< int Size, typename Element_ >  // template catches both const and non-const qualified Element
+   __cuda_callable__
+   ArrayView( const StaticArray< Size, Element_ >& array );
+
 
    // methods for rebinding (reinitialization)
    __cuda_callable__

src/TNL/Containers/ArrayView_impl.h

@@ -56,6 +56,28 @@ ArrayView( StaticArray< Size, Element_ >& array )
    this->bind( array.getData(), Size );
 }
 
+template< typename Element,
+          typename Device,
+          typename Index >
+   template< typename Element_ >
+__cuda_callable__
+ArrayView< Element, Device, Index >::
+ArrayView( const Array< Element_, Device, Index >& array )
+{
+   this->bind( array.getData(), array.getSize() );
+}
+
+template< typename Element,
+          typename Device,
+          typename Index >
+   template< int Size, typename Element_ >
+__cuda_callable__
+ArrayView< Element, Device, Index >::
+ArrayView( const StaticArray< Size, Element_ >& array )
+{
+   this->bind( array.getData(), Size );
+}
+
 // methods for rebinding (reinitialization)
 template< typename Element,
           typename Device,

src/UnitTests/Containers/ArrayViewTest.h

@@ -137,6 +137,7 @@ TYPED_TEST( ArrayViewTest, constructors )
 {
    using ArrayType = typename TestFixture::ArrayType;
    using ViewType = typename TestFixture::ViewType;
+   using ConstViewType = ArrayView< const typename ArrayType::ElementType, typename ArrayType::DeviceType, typename ArrayType::IndexType >;
 
    ArrayType a( 10 );
    EXPECT_EQ( a.getSize(), 10 );
@@ -154,6 +155,11 @@ TYPED_TEST( ArrayViewTest, constructors )
       EXPECT_EQ( z.getData(), data );
       EXPECT_EQ( z.getSize(), 10 );
    }
+
+   // test initialization by const reference
+   const ArrayType& b = a;
+   ConstViewType b_view( b );
+   ConstViewType const_a_view( a );
 }
 
 TYPED_TEST( ArrayViewTest, bind )