namespace re2c_test {
+/*
+ * If encoding has N code units (characters), character class can be
+ * represented as an N-bit integer: k-th bit is set iff k-th character
+ * belongs to the class.
+ *
+ * Addition and subtraction can be implemented trivially for such
+ * integer representation of character classes: addition is simply
+ * bitwise OR of two classes, subtraction is bitwise AND of the first
+ * class and negated second class.
+ */
template <uint8_t BITS> re2c::Range * range (uint32_t n);
template <uint8_t BITS> re2c::Range * add (uint32_t n1, uint32_t n2);
template <uint8_t BITS> re2c::Range * sub (uint32_t n1, uint32_t n2);