Merge pull request #289 from dalle/issue288-char8-support

Support char8_t on C++20

Author: dalle

README.md

@@ -149,7 +149,7 @@ int main() {
     std::cerr << "parsing failure\n";
     return EXIT_FAILURE;
   }
-  std::cout << "parsed the number "<< i << std::endl;
+  std::cout << "parsed the number " << i << std::endl;
 
   std::string binstr = "1001111000011001110110111001001010110100111000110001100";
 
@@ -158,7 +158,7 @@ int main() {
     std::cerr << "parsing failure\n";
     return EXIT_FAILURE;
   }
-  std::cout << "parsed the number "<< i << std::endl;
+  std::cout << "parsed the number " << i << std::endl;
 
   std::string hexstr = "4f0cedc95a718c";
 
@@ -167,7 +167,7 @@ int main() {
     std::cerr << "parsing failure\n";
     return EXIT_FAILURE;
   }
-  std::cout << "parsed the number "<< i << std::endl;
+  std::cout << "parsed the number " << i << std::endl;
   return EXIT_SUCCESS;
 }
 ```

include/fast_float/float_common.h

@@ -237,7 +237,12 @@ struct is_supported_char_type
     : std::integral_constant<bool, std::is_same<UC, char>::value ||
                                        std::is_same<UC, wchar_t>::value ||
                                        std::is_same<UC, char16_t>::value ||
-                                       std::is_same<UC, char32_t>::value> {};
+                                       std::is_same<UC, char32_t>::value
+#ifdef __cpp_char8_t
+                                       || std::is_same<UC, char8_t>::value
+#endif
+                             > {
+};
 
 // Compares two ASCII strings in a case insensitive manner.
 template <typename UC>
@@ -748,6 +753,11 @@ template <> constexpr char16_t const *str_const_nan<char16_t>() {
 template <> constexpr char32_t const *str_const_nan<char32_t>() {
   return U"nan";
 }
+#ifdef __cpp_char8_t
+template <> constexpr char8_t const *str_const_nan<char8_t>() {
+  return u8"nan";
+}
+#endif
 
 template <typename UC> constexpr UC const *str_const_inf();
 template <> constexpr char const *str_const_inf<char>() { return "infinity"; }
@@ -760,6 +770,11 @@ template <> constexpr char16_t const *str_const_inf<char16_t>() {
 template <> constexpr char32_t const *str_const_inf<char32_t>() {
   return U"infinity";
 }
+#ifdef __cpp_char8_t
+template <> constexpr char8_t const *str_const_inf<char8_t>() {
+  return u8"infinity";
+}
+#endif
 
 template <typename = void> struct int_luts {
   static constexpr uint8_t chdigit[] = {