diff --git a/exprtk.hpp b/exprtk.hpp
index 3e6f2b9..cde89f4 100644
--- a/exprtk.hpp
+++ b/exprtk.hpp
@@ -248,11 +248,6 @@ namespace exprtk
             return data_;
          }
 
-         inline operator const char* () const
-         {
-            return data_.data();
-         }
-
       private:
 
          std::string data_;
@@ -417,6 +412,8 @@ namespace exprtk
                                        10000000000000000.0,
                                     };
 
+     static const std::size_t pow10_size = sizeof(pow10) / sizeof(double);
+
       namespace numeric
       {
          namespace constant
@@ -607,14 +604,13 @@ namespace exprtk
                return ((v < T(0)) ? std::ceil(v - T(0.5)) : std::floor(v + T(0.5)));
             }
 
-            template <typename T>
-            inline T roundn_impl(const T v0, const T v1, real_type_tag)
-            {
-               // 0 <= index <= sizeof(pow10)
-               const int index = std::max<int>(0,std::min<int>(sizeof(pow10),(int)std::floor(v1)));
-               const T p10 = pow10[index];
-               return T(std::floor((v0 * p10) + T(0.5)) / p10);
-            }
+         template <typename T>
+         inline T roundn_impl(const T v0, const T v1, real_type_tag)
+         {
+            const int index = std::max<int>(0, std::min<int>(pow10_size - 1, (int)std::floor(v1)));
+            const T p10 = T(pow10[index]);
+            return T(std::floor((v0 * p10) + T(0.5)) / p10);
+         }
 
             template <typename T>
             inline T roundn_impl(const T v0, const T, int_type_tag)
diff --git a/exprtk_benchmark.cpp b/exprtk_benchmark.cpp
index cce68ab..109f70b 100644
--- a/exprtk_benchmark.cpp
+++ b/exprtk_benchmark.cpp
@@ -249,7 +249,7 @@ struct native
 
    static inline T func13(Type x, Type y)
    {
-      return (x + (std::cos(y - std::sin(2 / x * pi)) - std::sin(x - std::cos(2 * y / pi))) - y);
+      return (x + (std::cos(y - std::sin(T(2) / x * pi)) - std::sin(x - std::cos(T(2) * y / pi))) - y);
    }
 
    static inline T func14(Type x, Type y)
diff --git a/readme.txt b/readme.txt
index 5fa2652..9fd0706 100644
--- a/readme.txt
+++ b/readme.txt
@@ -481,7 +481,7 @@ correctly optimize such expressions for a given architecture.
    $f41(x,y,z) | x * log10(y)-z    $f88(x,y,z,w) | x*y^7 + z*w^7
    $f42(x,y,z) | x * sin(y)+z      $f89(x,y,z,w) | x*y^8 + z*w^8
    $f43(x,y,z) | x * sin(y)-z      $f90(x,y,z,w) | x*y^9 + z*w^9
-   $f44(x,y,z) | x * cos(y)+z      $f91(x,y,z,w) | (x and y) ? z
+   $f44(x,y,z) | x * cos(y)+z      $f91(x,y,z,w) | (x and y) ? z : w
    $f45(x,y,z) | x * cos(y)-z      $f92(x,y,z,w) | (x or  y) ? z : w
    $f46(x,y,z) | x ? y : z         $f93(x,y,z,w) | (x <   y) ? z : w
                                    $f94(x,y,z,w) | (x <=  y) ? z : w