# [performance][math] Replace std::pow(Scalar, int) with Dune::power(Scalar, int) or write product explicitly

A quick grep showed that we use `std::pow(Scalar, int)`

at quite a lot of places. Performance could be improved
by using `Dune::power(Scalar, int)`

(which is even `constexpr`

) for exponents > 2 or just by explicitly writing down the product.

```
Scalar result0 = std::pow(a, 2);
Scalar result1 = Dune::power(a, 2);
Scalar result2 = a*a;
```