common/alstring.h

   1 #ifndef AL_STRING_H
   2 #define AL_STRING_H
   3
   4 #include <algorithm>
   5 #include <cstddef>
   6 #include <limits>
   7 #include <string>
   8 #include <string_view>
   9
  10
  11 namespace al {
  12
  13 template<typename ...Ts>
  14 [[nodiscard]] constexpr
  15 auto sizei(const std::basic_string_view<Ts...> str) noexcept -> int
  16 { return static_cast<int>(std::min<std::size_t>(str.size(), std::numeric_limits<int>::max())); }
  17
  18 template<typename ...Ts>
  19 [[nodiscard]] constexpr
  20 auto sizei(const std::basic_string<Ts...> &str) noexcept -> int
  21 { return static_cast<int>(std::min<std::size_t>(str.size(), std::numeric_limits<int>::max())); }
  22
  23
  24 [[nodiscard]]
  25 constexpr bool contains(const std::string_view str0, const std::string_view str1) noexcept
  26 { return str0.find(str1) != std::string_view::npos; }
  27
  28 [[nodiscard]]
  29 constexpr bool starts_with(const std::string_view str0, const std::string_view str1) noexcept
  30 { return str0.substr(0, std::min(str0.size(), str1.size())) == str1; }
  31
  32 [[nodiscard]]
  33 constexpr bool ends_with(const std::string_view str0, const std::string_view str1) noexcept
  34 { return str0.substr(str0.size() - std::min(str0.size(), str1.size())) == str1; }
  35
  36 [[nodiscard]]
  37 int case_compare(const std::string_view str0, const std::string_view str1) noexcept;
  38
  39 [[nodiscard]]
  40 int case_compare(const std::wstring_view str0, const std::wstring_view str1) noexcept;
  41
  42 /* C++20 changes path::u8string() to return a string using a new/distinct
  43  * char8_t type for UTF-8 strings. However, support for this with standard
  44  * string functions is totally inadequate, and we already hold UTF-8 with plain
  45  * char strings. So this function is used to reinterpret a char8_t string as a
  46  * char string_view.
  47  */
  48 #if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201907L
  49 inline auto u8_as_char(const std::u8string_view str) -> std::string_view
  50 #else
  51 inline auto u8_as_char(const std::string_view str) -> std::string_view
  52 #endif
  53 {
  54     return std::string_view{reinterpret_cast<const char*>(str.data()), str.size()};
  55 }
  56
  57 } // namespace al
  58
  59 #endif /* AL_STRING_H */