⚡ improve comment parsing

include/nlohmann/detail/input/lexer.hpp

@@ -835,48 +835,40 @@ class lexer : public lexer_base<BasicJsonType>
      */
     bool scan_comment()
     {
-        // remember character after '/' to distinguish comment types
-        const auto comment_char = get();
-
-        // expect // or /* to start a comment
-        if (comment_char != '/' and comment_char != '*')
+        switch (get())
+        {
+            case '/':
             {
-            return false;
-        }
-
                 while (true)
                 {
                     switch (get())
                     {
-                // EOF inside a /* comment is an error, in // it is OK
-                case std::char_traits<char_type>::eof():
-                case '\0':
-                {
-                    return comment_char == '/';
-                }
-
-                // a newline ends the // comment
                         case '\n':
                         case '\r':
-                {
-                    if (comment_char == '/')
-                    {
                             return true;
-                    }
+
+                        default:
                             break;
                     }
+                }
+            }
 
-                // */ ends the /* comment
             case '*':
             {
-                    if (comment_char == '*')
+                while (true)
                 {
                     switch (get())
                     {
-                            case '/':
+                        case std::char_traits<char_type>::eof():
+                        case '\0':
+                            return false;
+
+                        case '*':
+                        {
+                            switch (get())
                             {
+                                case '/':
                                     return true;
-                            }
 
                                 default:
                                 {
@@ -885,12 +877,12 @@ class lexer : public lexer_base<BasicJsonType>
                                 }
                             }
                         }
-                    break;
+                    }
+                }
             }
 
             default:
-                    break;
-            }
+                return false;
         }
     }
 

single_include/nlohmann/json.hpp

@@ -8902,48 +8902,40 @@ class lexer : public lexer_base<BasicJsonType>
      */
     bool scan_comment()
     {
-        // remember character after '/' to distinguish comment types
-        const auto comment_char = get();
-
-        // expect // or /* to start a comment
-        if (comment_char != '/' and comment_char != '*')
+        switch (get())
+        {
+            case '/':
             {
-            return false;
-        }
-
                 while (true)
                 {
                     switch (get())
                     {
-                // EOF inside a /* comment is an error, in // it is OK
-                case std::char_traits<char_type>::eof():
-                case '\0':
-                {
-                    return comment_char == '/';
-                }
-
-                // a newline ends the // comment
                         case '\n':
                         case '\r':
-                {
-                    if (comment_char == '/')
-                    {
                             return true;
-                    }
+
+                        default:
                             break;
                     }
+                }
+            }
 
-                // */ ends the /* comment
             case '*':
             {
-                    if (comment_char == '*')
+                while (true)
                 {
                     switch (get())
                     {
-                            case '/':
+                        case std::char_traits<char_type>::eof():
+                        case '\0':
+                            return false;
+
+                        case '*':
+                        {
+                            switch (get())
                             {
+                                case '/':
                                     return true;
-                            }
 
                                 default:
                                 {
@@ -8952,12 +8944,12 @@ class lexer : public lexer_base<BasicJsonType>
                                 }
                             }
                         }
-                    break;
+                    }
+                }
             }
 
             default:
-                    break;
-            }
+                return false;
         }
     }