Modify implementation to match proposal

Specifically dealing with constraints and mandates.
See kokkos#66.

include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp

@@ -66,7 +66,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<extents<numRows_A, numCols_A> >::is_always_unique())
 void matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
@@ -124,7 +124,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
@@ -185,7 +185,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void symmetric_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,
@@ -263,7 +263,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void symmetric_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,
@@ -343,7 +343,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void hermitian_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,
@@ -392,7 +392,7 @@ template<class ExecutionPolicy,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void hermitian_matrix_vector_product(
   ExecutionPolicy&& /* exec */,
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
@@ -423,7 +423,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void hermitian_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,
@@ -505,7 +505,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void triangular_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,
@@ -593,7 +593,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
-  requires (Layout_A::is_always_unique())
+  requires (Layout_A::template mapping<std::experimental::extents<numRows_A, numCols_A>>::is_always_unique())
 void triangular_matrix_vector_product(
   std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
   Triangle t,