Resolve "Test cuda and codegen in CI"

src/core/cell/Cell.h

@@ -338,7 +338,7 @@ inline std::size_t hash_value( const Cell & cell )
 {
    std::size_t seed;
 
-   if constexpr( sizeof(std::size_t) >= 8 )
+   if( sizeof(std::size_t) >= 8 )
    {
       seed = (static_cast<std::size_t>(cell.x()) << 42) +
              (static_cast<std::size_t>(cell.y()) << 21) +

src/core/math/Vector2.h

@@ -1561,12 +1561,12 @@ struct Vector2LexicographicalyLess
 // \param   v The vector the hash is computed for.
 // \returns   A hash for the entire Vector2.
 */
-template< typename T, typename Enable = std::enable_if_t<std::is_integral_v<T>> >
+template< typename T, typename Enable = std::enable_if_t<std::is_integral<T>::value> >
 std::size_t hash_value( const Vector2<T> & v )
 {
    std::size_t seed;
 
-   if constexpr( sizeof(std::size_t) >= 8 )
+   if( sizeof(std::size_t) >= 8 )
    {
       seed = (static_cast<std::size_t>(v[0]) << 42) +
              (static_cast<std::size_t>(v[1]) << 21);

src/core/math/Vector3.h

@@ -1847,12 +1847,12 @@ struct Vector3LexicographicalyLess
 // \param   v The vector the hash is computed for.
 // \returns   A hash for the entire Vector3.
 */
-template< typename T, typename Enable = std::enable_if_t<std::is_integral_v<T>> >
+template< typename T, typename Enable = std::enable_if_t<std::is_integral<T>::value> >
 std::size_t hash_value( const Vector3<T> & v )
 {
    std::size_t seed;
 
-   if constexpr( sizeof(std::size_t) >= 8 )
+   if( sizeof(std::size_t) >= 8 )
    {
       seed = (static_cast<std::size_t>(v[0]) << 42) +
              (static_cast<std::size_t>(v[1]) << 21) +