Small cleanup of strtonumber implementation

dune/common/strtonumber.hh

@@ -236,7 +236,7 @@ namespace Dune
 
   /// Overload of \ref strTo for `std::string` arguments.
   template<typename T>
-  T strTo (std::string const& str) { return strTo<T>(str.c_str()); }
+  T strTo (const std::string& str) { return strTo<T>(str.c_str()); }
 
 } // end namespace Dune
 

dune/common/test/strtonumbertest.cc

@@ -142,7 +142,7 @@ int main()
 
     Comparator<T> cmp{};
     Generator<T> generate{};
-    for (int i = 0; i < 100; ++i) { // repeat the test 10 times
+    for (int i = 0; i < 100; ++i) { // repeat the test 100 times
       value = generate();
       std::ostringstream oss;
       oss << std::setprecision(std::numeric_limits<T>::digits10 + 3) << value;