c++1.0—–源码分析正则表达式的错误类型

 1 namespace regex_constants
 2 {
 3 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 4 
 5   /**
 6    * @name 5.3 Error Types
 7    */
 8   //@{
 9 
10   enum error_type
11     {
12       _S_error_collate,
13       _S_error_ctype,
14       _S_error_escape,
15       _S_error_backref,
16       _S_error_brack,
17       _S_error_paren,
18       _S_error_brace,
19       _S_error_badbrace,
20       _S_error_range,
21       _S_error_space,
22       _S_error_badrepeat,
23       _S_error_complexity,
24       _S_error_stack,
25     };
26 
27   /** The expression contained an invalid collating element name. */
28   constexpr error_type error_collate(_S_error_collate);
29 
30   /** The expression contained an invalid character class name. */
31   constexpr error_type error_ctype(_S_error_ctype);
32 
33   /**
34    * The expression contained an invalid escaped character, or a trailing
35    * escape.
36    */
37   constexpr error_type error_escape(_S_error_escape);
38 
39   /** The expression contained an invalid back reference. */
40   constexpr error_type error_backref(_S_error_backref);
41 
42   /** The expression contained mismatched [ and ]. */
43   constexpr error_type error_brack(_S_error_brack);
44 
45   /** The expression contained mismatched ( and ). */
46   constexpr error_type error_paren(_S_error_paren);
47 
48   /** The expression contained mismatched { and } */
49   constexpr error_type error_brace(_S_error_brace);
50 
51   /** The expression contained an invalid range in a {} expression. */
52   constexpr error_type error_badbrace(_S_error_badbrace);
53 
54   /**
55    * The expression contained an invalid character range,
56    * such as [b-a] in most encodings.
57    */
58   constexpr error_type error_range(_S_error_range);
59 
60   /**
61    * There was insufficient memory to convert the expression into a
62    * finite state machine.
63    */
64   constexpr error_type error_space(_S_error_space);
65 
66   /**
67    * One of <em>*?+{</em> was not preceded by a valid regular expression.
68    */
69   constexpr error_type error_badrepeat(_S_error_badrepeat);
70 
71   /**
72    * The complexity of an attempted match against a regular expression
73    * exceeded a pre-set level.
74    */
75   constexpr error_type error_complexity(_S_error_complexity);
76 
77   /**
78    * There was insufficient memory to determine whether the
79    * regular expression could match the specified character sequence.
80    */
81   constexpr error_type error_stack(_S_error_stack);
82 
83   //@}
84 _GLIBCXX_END_NAMESPACE_VERSION
85 }

1 try {
2         regex r("[[:alnum:]]+\.cpp|cxx|cc)$", regex::icase);
3     } catch (regex_error e)
4     { cout << e.what() << "ncode: " << e.code() << endl; }