//: C17:ichar_traits.h
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Creating your own character traits
#ifndef ICHAR_TRAITS_H
#define ICHAR_TRAITS_H
#include <string>
#include <cctype>

struct ichar_traits : std::char_traits<char> {
  // We'll only change character by 
  // character comparison functions
  static bool eq(char c1st, char c2nd) {
    return 
      std::toupper(c1st) == std::toupper(c2nd);
  }
  static bool ne(char c1st, char c2nd) {
    return 
      std::toupper(c1st) != std::toupper(c2nd);
  }
  static bool lt(char c1st, char c2nd) {
    return 
      std::toupper(c1st) < std::toupper(c2nd);
  }
  static int compare(const char* str1, 
    const char* str2, size_t n) {
    for(int i = 0; i < n; i++) {
      if(std::tolower(*str1)>std::tolower(*str2))
        return 1;
      if(std::tolower(*str1)<std::tolower(*str2))
        return -1;
      if(*str1 == 0 || *str2 == 0)
        return 0;
      str1++; str2++; // Compare the other chars
    }
    return 0;
  }
  static const char* find(const char* s1, 
    int  n, char c) {
    while(n-- > 0 &&  
      std::toupper(*s1) != std::toupper(c))
      s1++;
    return s1;
  }
};
#endif // ICHAR_TRAITS_H  ///:~