insert has one progress

include/matador/utils/string.hpp

@@ -22,6 +22,16 @@ MATADOR_UTILS_API std::string to_string(const blob_type_t &data);
 MATADOR_UTILS_API std::string to_string(const date_type_t &data);
 MATADOR_UTILS_API std::string to_string(const time_type_t &data);
 
+template <typename IntegerType>
+std::string to_hex_string(IntegerType data, const size_t width = sizeof(IntegerType)<<1) {
+  static auto digits = "0123456789ABCDEF";
+  std::string result(width,'0');
+  for (size_t i=0, j=(width-1)*4 ; i<width; ++i,j-=4) {
+    result[i] = digits[(data>>j) & 0x0f];
+  }
+  return result;
+}
+
 /**
  * Splits a string by a delimiter and
  * add the string tokens to a vector. The