iwchar_traits.h

C语言数值算法程序大全（第二版）,课本文件

//: C03:iwchar_traits.h
// From "Thinking in C++, 2nd Edition, Volume 2"
// by Bruce Eckel & Chuck Allison, (c) 2003 MindView, Inc.
// Available at www.BruceEckel.com.
//{-bor}
//{-g++}
// Creating your own wide-character traits
#ifndef IWCHAR_TRAITS_H
#define IWCHAR_TRAITS_H
#include <cassert>
#include <cwctype>
#include <cmath>
#include <ostream>
#include <string>

using std::towupper;
using std::towlower;
using std::wostream;
using std::wstring;
using std::char_traits;
using std::allocator;
using std::basic_string;

struct iwchar_traits : char_traits<wchar_t> {
  // We'll only change character-by-
  // character comparison functions
  static bool eq(wchar_t c1st, wchar_t c2nd) {
    return towupper(c1st) == towupper(c2nd);
  }
  static bool ne(wchar_t c1st, wchar_t c2nd) {
    return towupper(c1st) != towupper(c2nd);
  }
  static bool lt(wchar_t c1st, wchar_t c2nd) {
    return towupper(c1st) < towupper(c2nd);
  }
  static int compare(const wchar_t* str1, 
    const wchar_t* str2, size_t n) {
    for(size_t i = 0; i < n; i++) {
      if(str1 == 0)
        return -1;
      else if(str2 == 0)
        return 1;
      else if(towlower(*str1) < towlower(*str2))
        return -1;
      else if(towlower(*str1) > towlower(*str2))
        return 1;
      assert(towlower(*str1) == towlower(*str2));
      str1++; str2++; // Compare the other wchar_ts
    }
    return 0;
  }
  static const wchar_t* find(const wchar_t* s1, 
    size_t n, wchar_t c) {
    while(n-- > 0)
      if(towupper(*s1) == towupper(c))
        return s1;
      else
        ++s1;
    return 0;
  }
};

typedef basic_string<wchar_t, iwchar_traits> iwstring;

inline wostream& operator<<(wostream& os,
  const iwstring& s) {
  return os << wstring(s.c_str(), s.length());
}
#endif // IWCHAR_TRAITS_H  ///:~