-float almost_equals(float a, float b);
-float almost_in_bounds(float a, float b, float c);
-
-float power2of(float e);
-float log2of(float x);
-
-vector rgb_to_hsl(vector rgb);
-vector hsl_to_rgb(vector hsl);
-vector rgb_to_hsv(vector rgb);
-vector hsv_to_rgb(vector hsv);
-string rgb_to_hexcolor(vector rgb);
-
-float boxesoverlap(vector m1, vector m2, vector m3, vector m4);
-float boxinsidebox(vector smins, vector smaxs, vector bmins, vector bmaxs);
-
-typedef float(string s, vector size) textLengthUpToWidth_widthFunction_t;
-typedef float(string s) textLengthUpToLength_lenFunction_t;
+USING(textLengthUpToWidth_widthFunction_t, float(string s, vector size));
+USING(textLengthUpToLength_lenFunction_t, float(string s));