diff --git a/include/experimental/__p1673_bits/blas1_dot.hpp b/include/experimental/__p1673_bits/blas1_dot.hpp
index 2fa00f7c..2f986f86 100644
--- a/include/experimental/__p1673_bits/blas1_dot.hpp
+++ b/include/experimental/__p1673_bits/blas1_dot.hpp
@@ -63,6 +63,10 @@ Scalar dot(std::experimental::mdspan<ElementType1, std::experimental::extents<ex
            std::experimental::mdspan<ElementType2, std::experimental::extents<ext2>, Layout2, Accessor2> v2,
            Scalar init)
 {
+  static_assert(v1.static_extent(0) == dynamic_extent ||
+                v2.static_extent(0) == dynamic_extent ||
+                v1.static_extent(0) == v2.static_extent(0));
+  
   for (size_t k = 0; k < v1.extent(0); ++k) {
     init += v1(k) * v2(k);
   }
diff --git a/include/experimental/__p1673_bits/blas1_givens.hpp b/include/experimental/__p1673_bits/blas1_givens.hpp
index 3370af4d..f12d521b 100644
--- a/include/experimental/__p1673_bits/blas1_givens.hpp
+++ b/include/experimental/__p1673_bits/blas1_givens.hpp
@@ -359,6 +359,10 @@ void givens_rotation_apply(
   const Real c,
   const Real s)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
   for (extents<>::size_type i = 0; i < x.extent(0); ++i) {
     const auto dtemp = c * x(i) + s * y(i);
     y(i) = c * y(i) - s * x(i);
@@ -401,6 +405,10 @@ void givens_rotation_apply(
   const Real c,
   const complex<Real> s)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
   using std::conj;
   for (extents<>::size_type i = 0; i < x.extent(0); ++i) {
     const auto dtemp = c * x(i) + s * y(i);
diff --git a/include/experimental/__p1673_bits/blas1_linalg_add.hpp b/include/experimental/__p1673_bits/blas1_linalg_add.hpp
index 0ec725fc..f3e23888 100644
--- a/include/experimental/__p1673_bits/blas1_linalg_add.hpp
+++ b/include/experimental/__p1673_bits/blas1_linalg_add.hpp
@@ -67,6 +67,16 @@ void add_rank_1(
   std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
   std::experimental::mdspan<ElementType_z, std::experimental::extents<ext_z>, Layout_z, Accessor_z> z)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                z.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == z.static_extent(0));
+  static_assert(y.static_extent(0) == dynamic_extent ||
+                z.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == z.static_extent(0));
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
   for (extents<>::size_type i = 0; i < z.extent(0); ++i) {
     z(i) = x(i) + y(i);
   }
@@ -92,6 +102,26 @@ void add_rank_2(
   std::experimental::mdspan<ElementType_y, std::experimental::extents<numRows_y, numCols_y>, Layout_y, Accessor_y> y,
   std::experimental::mdspan<ElementType_z, std::experimental::extents<numRows_z, numCols_z>, Layout_z, Accessor_z> z)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                z.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == z.static_extent(0));
+  static_assert(y.static_extent(0) == dynamic_extent ||
+                z.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == z.static_extent(0));
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
+  static_assert(x.static_extent(1) == dynamic_extent ||
+                z.static_extent(1) == dynamic_extent ||
+                x.static_extent(1) == z.static_extent(1));
+  static_assert(y.static_extent(1) == dynamic_extent ||
+                z.static_extent(1) == dynamic_extent ||
+                y.static_extent(1) == z.static_extent(1));
+  static_assert(x.static_extent(1) == dynamic_extent ||
+                y.static_extent(1) == dynamic_extent ||
+                x.static_extent(1) == y.static_extent(1));
+
   using size_type = typename extents<>::size_type;
 
   for (size_type j = 0; j < x.extent(1); ++j) {
diff --git a/include/experimental/__p1673_bits/blas1_linalg_copy.hpp b/include/experimental/__p1673_bits/blas1_linalg_copy.hpp
index 2032c1f8..b8f1e86f 100644
--- a/include/experimental/__p1673_bits/blas1_linalg_copy.hpp
+++ b/include/experimental/__p1673_bits/blas1_linalg_copy.hpp
@@ -62,6 +62,10 @@ void copy_rank_1(
   std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
   std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
   for (extents<>::size_type i = 0; i < y.extent(0); ++i) {
     y(i) = x(i);
   }
@@ -81,6 +85,13 @@ void copy_rank_2(
   std::experimental::mdspan<ElementType_x, std::experimental::extents<numRows_x, numCols_x>, Layout_x, Accessor_x> x,
   std::experimental::mdspan<ElementType_y, std::experimental::extents<numRows_y, numCols_y>, Layout_y, Accessor_y> y)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+  static_assert(x.static_extent(1) == dynamic_extent ||
+                y.static_extent(1) == dynamic_extent ||
+                x.static_extent(1) == y.static_extent(1));
+
   using size_type = typename extents<>::size_type;
 
   for (size_type j = 0; j < y.extent(1); ++j) {
diff --git a/include/experimental/__p1673_bits/blas1_linalg_swap.hpp b/include/experimental/__p1673_bits/blas1_linalg_swap.hpp
index 6131e942..36e832ac 100644
--- a/include/experimental/__p1673_bits/blas1_linalg_swap.hpp
+++ b/include/experimental/__p1673_bits/blas1_linalg_swap.hpp
@@ -64,6 +64,10 @@ void swap_rank_1(
   std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
   std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+
   using std::swap;
   using size_type = typename extents<>::size_type;
 
@@ -86,6 +90,13 @@ void swap_rank_2(
   std::experimental::mdspan<ElementType_x, std::experimental::extents<numRows_x, numCols_x>, Layout_x, Accessor_x> x,
   std::experimental::mdspan<ElementType_y, std::experimental::extents<numRows_y, numCols_y>, Layout_y, Accessor_y> y)
 {
+  static_assert(x.static_extent(0) == dynamic_extent ||
+                y.static_extent(0) == dynamic_extent ||
+                x.static_extent(0) == y.static_extent(0));
+  static_assert(x.static_extent(1) == dynamic_extent ||
+                y.static_extent(1) == dynamic_extent ||
+                x.static_extent(1) == y.static_extent(1));
+
   using std::swap;
   using size_type = typename extents<>::size_type;
 
@@ -111,10 +122,10 @@ void swap_elements(
   std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x ...>, Layout_x, Accessor_x> x,
   std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y ...>, Layout_y, Accessor_y> y)
 {
-  if constexpr (x.rank() == 1) {
+  if constexpr (x.rank() == 1 && y.rank() == 1) {
     swap_rank_1(x, y);
   }
-  else if constexpr (x.rank() == 2) {
+  else if constexpr (x.rank() == 2 && y.rank() == 2) {
     swap_rank_2(x, y);
   }
   else {
diff --git a/include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp b/include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp
index 1231cefe..2aa23053 100644
--- a/include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp
+++ b/include/experimental/__p1673_bits/blas2_matrix_vector_product.hpp
@@ -66,6 +66,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
+  requires (Layout_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,
@@ -123,6 +124,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
+  requires (Layout_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,
@@ -183,6 +185,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
+  requires (Layout_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,
@@ -260,6 +263,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
+  requires (Layout_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,
@@ -339,6 +343,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
+  requires (Layout_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,
@@ -387,6 +392,7 @@ template<class ExecutionPolicy,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
+  requires (Layout_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,
@@ -417,6 +423,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
+  requires (Layout_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,
@@ -498,6 +505,7 @@ template<class ElementType_A,
          extents<>::size_type ext_y,
          class Layout_y,
          class Accessor_y>
+  requires (Layout_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,
@@ -585,6 +593,7 @@ template<class ElementType_A,
          extents<>::size_type ext_z,
          class Layout_z,
          class Accessor_z>
+  requires (Layout_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,