std::regex_traits< _Ch_type > Class 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>
class 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 80 of file regex.h.

Constructor & Destructor Documentation

regex_traits()

template<typename _Ch_type>

std::regex_traits< _Ch_type >::regex_traits ( )

inline

Constructs a default traits object.

Definition at line 157 of file regex.h.

Member Function Documentation

getloc()

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 370 of file regex.h.

imbue()

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

__loc

A 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 359 of file regex.h.

isctype()

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

__c	a character.
__f	a 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_cast

if the current locale does not have a ctype facet.

Definition at line 327 of file regex.tcc.

length()

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

__p	a 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 170 of file regex.h.

lookup_classname()

template<typename _Ch_type >

template<typename _Fwd_iter >

regex_traits< _Ch_type >::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

__first	beginning of the character sequence.
__last	one-past-the-end of the character sequence.
__icase	ignores 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

Definition at line 283 of file regex.tcc.

lookup_collatename()

template<typename _Ch_type >

template<typename _Fwd_iter >

regex_traits< _Ch_type >::string_type std::regex_traits< _Ch_type >::lookup_collatename	(	_Fwd_iter	__first,
		_Fwd_iter	__last
	)		const

Gets a collation element by name.

Parameters

__first	beginning of the collation element name.
__last	one-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.

Definition at line 127 of file regex.tcc.

transform()

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

__first	beginning of the character sequence.
__last	one-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_cast

if the current locale does not have a collate facet.

Definition at line 223 of file regex.h.

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

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

__first	beginning of the character sequence.
__last	one-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 247 of file regex.h.

translate()

template<typename _Ch_type>

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

inline

Performs the identity translation.

Parameters

__c	A character to the locale-specific character set.

Returns

__c.

Definition at line 181 of file regex.h.

translate_nocase()

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

__c	A character to the locale-specific character set.

Returns

the locale-specific lower-case equivalent of __c.

Exceptions

std::bad_cast

if the imbued locale does not support the ctype facet.

Definition at line 194 of file regex.h.

value()

template<typename _Ch_type>

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

Converts a digit to an int.

Parameters

__ch	a character representing a digit.
__radix	the 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.

Definition at line 341 of file regex.tcc.

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The documentation for this class was generated from the following files:

• regex.h
• regex.tcc