common/alstring.cpp

   1
   2 #include "config.h"
   3
   4 #include "alstring.h"
   5
   6 #include <algorithm>
   7 #include <cctype>
   8 #include <cwctype>
   9 #include <cstring>
  10
  11
  12 namespace al {
  13
  14 int case_compare(const std::string_view str0, const std::string_view str1) noexcept
  15 {
  16     using Traits = std::string_view::traits_type;
  17
  18     auto ch0 = str0.cbegin();
  19     auto ch1 = str1.cbegin();
  20     auto ch1end = ch1 + std::min(str0.size(), str1.size());
  21     while(ch1 != ch1end)
  22     {
  23         const int u0{std::toupper(Traits::to_int_type(*ch0))};
  24         const int u1{std::toupper(Traits::to_int_type(*ch1))};
  25         if(const int diff{u0-u1}) return diff;
  26         ++ch0; ++ch1;
  27     }
  28
  29     if(str0.size() < str1.size()) return -1;
  30     if(str0.size() > str1.size()) return 1;
  31     return 0;
  32 }
  33
  34 int case_compare(const std::wstring_view str0, const std::wstring_view str1) noexcept
  35 {
  36     using Traits = std::wstring_view::traits_type;
  37
  38     auto ch0 = str0.cbegin();
  39     auto ch1 = str1.cbegin();
  40     auto ch1end = ch1 + std::min(str0.size(), str1.size());
  41     while(ch1 != ch1end)
  42     {
  43         const auto u0 = std::towupper(Traits::to_int_type(*ch0));
  44         const auto u1 = std::towupper(Traits::to_int_type(*ch1));
  45         if(const auto diff = static_cast<int>(u0-u1)) return diff;
  46         ++ch0; ++ch1;
  47     }
  48
  49     if(str0.size() < str1.size()) return -1;
  50     if(str0.size() > str1.size()) return 1;
  51     return 0;
  52 }
  53
  54 } // namespace al