libstdc++
std::regex_traits< _Ch_type > Struct Template Reference

Public Types

typedef _RegexMask char_class_type
 
typedef _Ch_type char_type
 
typedef std::locale locale_type
 
typedef std::basic_string
< char_type > 
string_type
 

Public Member Functions

 regex_traits ()
 
locale_type getloc () const
 
locale_type imbue (locale_type __loc)
 
bool isctype (_Ch_type __c, char_class_type __f) const
 
template<typename _Fwd_iter >
char_class_type lookup_classname (_Fwd_iter __first, _Fwd_iter __last, bool __icase=false) const
 
template<typename _Fwd_iter >
string_type lookup_collatename (_Fwd_iter __first, _Fwd_iter __last) const
 
template<typename _Fwd_iter >
string_type transform (_Fwd_iter __first, _Fwd_iter __last) const
 
template<typename _Fwd_iter >
string_type transform_primary (_Fwd_iter __first, _Fwd_iter __last) const
 
char_type translate (char_type __c) const
 
char_type translate_nocase (char_type __c) const
 
int value (_Ch_type __ch, int __radix) const
 

Static Public Member Functions

static std::size_t length (const char_type *__p)
 

Protected Attributes

locale_type _M_locale
 

Detailed Description

template<typename _Ch_type>
struct std::regex_traits< _Ch_type >

Describes aspects of a regular expression.

A regular expression traits class that satisfies the requirements of section [28.7].

The class regex is parameterized around a set of related types and functions used to complete the definition of its semantics. This class satisfies the requirements of such a traits class.

Definition at line 91 of file regex.h.

Constructor & Destructor Documentation

template<typename _Ch_type >
std::regex_traits< _Ch_type >::regex_traits ( )
inline

Constructs a default traits object.

Definition at line 171 of file regex.h.

Member Function Documentation

template<typename _Ch_type >
locale_type std::regex_traits< _Ch_type >::getloc ( ) const
inline

Gets a copy of the current locale in use by the regex_traits object.

Definition at line 384 of file regex.h.

template<typename _Ch_type >
locale_type std::regex_traits< _Ch_type >::imbue ( locale_type  __loc)
inline

Imbues the regex_traits object with a copy of a new locale.

Parameters
__locA locale.
Returns
a copy of the previous locale in use by the regex_traits object.
Note
Calling imbue with a different locale than the one currently in use invalidates all cached data held by *this.

Definition at line 373 of file regex.h.

References std::swap().

template<typename _Ch_type >
bool std::regex_traits< _Ch_type >::isctype ( _Ch_type  __c,
char_class_type  __f 
) const

Determines if c is a member of an identified class.

Parameters
__ca character.
__fa class type (as returned from lookup_classname).
Returns
true if the character __c is a member of the classification represented by __f, false otherwise.
Exceptions
std::bad_castif the current locale does not have a ctype facet.
template<typename _Ch_type >
static std::size_t std::regex_traits< _Ch_type >::length ( const char_type *  __p)
inlinestatic

Gives the length of a C-style string starting at __p.

Parameters
__pa pointer to the start of a character sequence.
Returns
the number of characters between *__p and the first default-initialized value of type char_type. In other words, uses the C-string algorithm for determining the length of a sequence of characters.

Definition at line 184 of file regex.h.

template<typename _Ch_type >
template<typename _Fwd_iter >
char_class_type std::regex_traits< _Ch_type >::lookup_classname ( _Fwd_iter  __first,
_Fwd_iter  __last,
bool  __icase = false 
) const

Maps one or more characters to a named character classification.

Parameters
__firstbeginning of the character sequence.
__lastone-past-the-end of the character sequence.
__icaseignores the case of the classification name.
Returns
an unspecified value that represents the character classification named by the character sequence designated by the iterator range [__first, __last). If icase is true, the returned mask identifies the classification regardless of the case of the characters to be matched (for example, [[:lower:]] is the same as [[:alpha:]]), otherwise a case-dependent classification is returned. The value returned shall be independent of the case of the characters in the character sequence. If the name is not recognized then returns a value that compares equal to 0.

At least the following names (or their wide-character equivalent) are supported.

  • d
  • w
  • s
  • alnum
  • alpha
  • blank
  • cntrl
  • digit
  • graph
  • lower
  • print
  • punct
  • space
  • upper
  • xdigit
template<typename _Ch_type >
template<typename _Fwd_iter >
string_type std::regex_traits< _Ch_type >::lookup_collatename ( _Fwd_iter  __first,
_Fwd_iter  __last 
) const

Gets a collation element by name.

Parameters
__firstbeginning of the collation element name.
__lastone-past-the-end of the collation element name.
Returns
a sequence of one or more characters that represents the collating element consisting of the character sequence designated by the iterator range [__first, __last). Returns an empty string if the character sequence is not a valid collating element.
template<typename _Ch_type >
template<typename _Fwd_iter >
string_type std::regex_traits< _Ch_type >::transform ( _Fwd_iter  __first,
_Fwd_iter  __last 
) const
inline

Gets a sort key for a character sequence.

Parameters
__firstbeginning of the character sequence.
__lastone-past-the-end of the character sequence.

Returns a sort key for the character sequence designated by the iterator range [F1, F2) such that if the character sequence [G1, G2) sorts before the character sequence [H1, H2) then v.transform(G1, G2) < v.transform(H1, H2).

What this really does is provide a more efficient way to compare a string to multiple other strings in locales with fancy collation rules and equivalence classes.

Returns
a locale-specific sort key equivalent to the input range.
Exceptions
std::bad_castif the current locale does not have a collate facet.

Definition at line 237 of file regex.h.

References std::basic_string< _CharT, _Traits, _Alloc >::data(), and std::basic_string< _CharT, _Traits, _Alloc >::size().

Referenced by std::regex_traits< _Ch_type >::transform_primary().

template<typename _Ch_type >
template<typename _Fwd_iter >
string_type std::regex_traits< _Ch_type >::transform_primary ( _Fwd_iter  __first,
_Fwd_iter  __last 
) const
inline

Gets a sort key for a character sequence, independent of case.

Parameters
__firstbeginning of the character sequence.
__lastone-past-the-end of the character sequence.

Effects: if typeid(use_facet<collate<_Ch_type> >) == typeid(collate_byname<_Ch_type>) and the form of the sort key returned by collate_byname<_Ch_type>::transform(__first, __last) is known and can be converted into a primary sort key then returns that key, otherwise returns an empty string.

Todo:
Implement this function correctly.

Definition at line 261 of file regex.h.

References std::vector< _Tp, _Alloc >::data(), std::vector< _Tp, _Alloc >::size(), and std::regex_traits< _Ch_type >::transform().

template<typename _Ch_type >
char_type std::regex_traits< _Ch_type >::translate ( char_type  __c) const
inline

Performs the identity translation.

Parameters
__cA character to the locale-specific character set.
Returns
__c.

Definition at line 195 of file regex.h.

template<typename _Ch_type >
char_type std::regex_traits< _Ch_type >::translate_nocase ( char_type  __c) const
inline

Translates a character into a case-insensitive equivalent.

Parameters
__cA character to the locale-specific character set.
Returns
the locale-specific lower-case equivalent of __c.
Exceptions
std::bad_castif the imbued locale does not support the ctype facet.

Definition at line 208 of file regex.h.

template<typename _Ch_type >
int std::regex_traits< _Ch_type >::value ( _Ch_type  __ch,
int  __radix 
) const

Converts a digit to an int.

Parameters
__cha character representing a digit.
__radixthe radix if the numeric conversion (limited to 8, 10, or 16).
Returns
the value represented by the digit __ch in base radix if the character __ch is a valid digit in base radix; otherwise returns -1.

The documentation for this struct was generated from the following file: