Better INT to HEX conversion.

Reimplementation of `4e96a41b4ee6bbc920b7c5a5ec555d6d14e65b18`,
`bb0b767ba40d189b97ffe371ab063c5380609b0c` and
`e36dae20b7d1baba912c55ec55b82a380c4973da` from old origin.

hex_functions.cpp

@@ -4,7 +4,7 @@
 
 namespace omni
 {
-  char halfword_to_hex_char(unsigned int input)
+  /*char halfword_to_hex_char(unsigned int input)
   {
     if (input > 127)
       return 'F';
@@ -46,38 +46,19 @@ namespace omni
     default:
       return 'F';
     }
-  }
+  }*/
 
   std::string int_to_hex(unsigned int input)
   {
     if (input > 255)
       return "FF";
 
-    std::bitset<8> whole_byte(input);
-    //240 represents 11110000, our needed bitmask
-    uint8_t left_mask_int = 240;
-    std::bitset<8> left_mask(left_mask_int);
-    std::bitset<8> left_halfword((whole_byte & left_mask) >> 4);
-    //likewise, 15 represents 00001111
-    uint8_t right_mask_int = 15;
-    std::bitset<8> right_mask(right_mask_int);
-    std::bitset<8> right_halfword((whole_byte & right_mask));
+    std::stringstream stream;
+    stream << std::setfill('0') << std::setw(sizeof(char)*2)
+         << std::hex << input;
+    std::string result(stream.str());
+    std::transform(result.begin(), result.end(), result.begin(), ::toupper);
 
-    unsigned int left = left_halfword.to_ulong();
-    unsigned int right = right_halfword.to_ulong();
-
-    //std::cout << "now have have " << left << " and " << right << '\n';
-
-    char a = halfword_to_hex_char(left);
-    char b = halfword_to_hex_char(right);
-
-    std::string left_string(1, a);
-    std::string right_string(1, b);
-
-    std::string final_byte = left_string + right_string;
-
-    //std::string final_byte = halfword_to_hex_char(left) + "" + halfword_to_hex_char(right);
-
-    return final_byte;
+    return result;
   }
 } //namespace omni

hex_functions.h

@@ -4,10 +4,14 @@
 #include <bitset>
 #include <cstdint>
 #include <iostream>
+#include <algorithm>
+#include <string>
+#include <iomanip>
+#include <sstream>
 
 namespace omni
 {
-  char halfword_to_hex_char(unsigned int input);
+  //char halfword_to_hex_char(unsigned int input);
   std::string int_to_hex(unsigned int input);
 }