std::ctype man page

std::ctype< _CharT > — Primary class template ctype facet.

This template class defines classification and conversion functions for character sets. It wraps cctype functionality. Ctype gets used by streams for many I/O operations.

Synopsis

Inherits std::__ctype_abstract_base< _CharT >.

Inherited by std::ctype_byname< _CharT >.

Public Types

typedef const int * __to_type

typedef _CharT char_type

typedef __ctype_abstract_base< _CharT >::mask mask

Public Member Functions

ctype (size_t __refs=0)

bool is (mask __m, char_type __c) const
Test char_type classification.
const char_type * is (const char_type *__lo, const char_type *__hi, mask *__vec) const
Return a mask array.
char narrow (char_type __c, char __dfault) const
Narrow char_type to char.
const char_type * narrow (const char_type *__lo, const char_type *__hi, char __dfault, char *__to) const
Narrow array to char array.
const char_type * scan_is (mask __m, const char_type *__lo, const char_type *__hi) const
Find char_type matching a mask.
const char_type * scan_not (mask __m, const char_type *__lo, const char_type *__hi) const
Find char_type not matching a mask.
char_type tolower (char_type __c) const
Convert to lowercase.
const char_type * tolower (char_type *__lo, const char_type *__hi) const
Convert array to lowercase.
char_type toupper (char_type __c) const
Convert to uppercase.
const char_type * toupper (char_type *__lo, const char_type *__hi) const
Convert array to uppercase.
char_type widen (char __c) const
Widen char to char_type.
const char * widen (const char *__lo, const char *__hi, char_type *__to) const
Widen array to char_type.

Static Public Attributes

static const mask alnum

static const mask alpha

static const mask blank

static const mask cntrl

static const mask digit

static const mask graph

static locale::id id
The facet id for ctype<char_type>
static const mask lower

static const mask print

static const mask punct

static const mask space

static const mask upper

static const mask xdigit

Protected Member Functions

virtual bool do_is (mask __m, char_type __c) const
Test char_type classification.
virtual const char_type * do_is (const char_type *__lo, const char_type *__hi, mask *__vec) const
Return a mask array.
virtual char do_narrow (char_type, char __dfault) const
Narrow char_type to char.
virtual const char_type * do_narrow (const char_type *__lo, const char_type *__hi, char __dfault, char *__to) const
Narrow char_type array to char.
virtual const char_type * do_scan_is (mask __m, const char_type *__lo, const char_type *__hi) const
Find char_type matching mask.
virtual const char_type * do_scan_not (mask __m, const char_type *__lo, const char_type *__hi) const
Find char_type not matching mask.
virtual char_type do_tolower (char_type __c) const
Convert to lowercase.
virtual const char_type * do_tolower (char_type *__lo, const char_type *__hi) const
Convert array to lowercase.
virtual char_type do_toupper (char_type __c) const
Convert to uppercase.
virtual const char_type * do_toupper (char_type *__lo, const char_type *__hi) const
Convert array to uppercase.
virtual char_type do_widen (char __c) const
Widen char.
virtual const char * do_widen (const char *__lo, const char *__hi, char_type *__dest) const
Widen char array.

Static Protected Member Functions

static __c_locale _S_clone_c_locale (__c_locale &__cloc) throw ()

static void _S_create_c_locale (__c_locale &__cloc, const char *__s, __c_locale __old=0)

static void _S_destroy_c_locale (__c_locale &__cloc)

static __c_locale _S_get_c_locale ()

static const char * _S_get_c_name () throw ()

static __c_locale _S_lc_ctype_c_locale (__c_locale __cloc, const char *__s)

Detailed Description

template<typename _CharT>

class std::ctype< _CharT >" Primary class template ctype facet.

This template class defines classification and conversion functions for character sets. It wraps cctype functionality. Ctype gets used by streams for many I/O operations.

This template provides the protected virtual functions the developer will have to replace in a derived class or specialization to make a working facet. The public functions that access them are defined in __ctype_abstract_base, to allow for implementation flexibility. See ctype<wchar_t> for an example. The functions are documented in __ctype_abstract_base.

Note: implementations are provided for all the protected virtual functions, but will likely not be useful.

Definition at line 612 of file locale_facets.h.

Member Function Documentation

template<typename _CharT> virtual bool std::ctype< _CharT >::do_is (mask __m, char_type __c) const [protected], [virtual]

Test char_type classification. This function finds a mask M for c and compares it to mask m.

do_is() is a hook for a derived facet to change the behavior of classifying. do_is() must always return the same result for the same input.

Parameters:

__c The char_type to find the mask of.
__m The mask to compare against.

Returns:

(M & __m) != 0.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_is (const char_type * __lo, const char_type * __hi, mask * __vec) const [protected], [virtual]

Return a mask array. This function finds the mask for each char_type in the range [lo,hi) and successively writes it to vec. vec must have as many elements as the input.

do_is() is a hook for a derived facet to change the behavior of classifying. do_is() must always return the same result for the same input.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.
__vec Pointer to an array of mask storage.

Returns:

__hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual char std::ctype< _CharT >::do_narrow (char_type __c, char __dfault) const [protected], [virtual]

Narrow char_type to char. This virtual function converts the argument to char using the simplest reasonable transformation. If the conversion fails, dfault is returned instead.

do_narrow() is a hook for a derived facet to change the behavior of narrowing. do_narrow() must always return the same result for the same input.

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__c The char_type to convert.
__dfault Char to return if conversion fails.

Returns:

The converted char.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_narrow (const char_type * __lo, const char_type * __hi, char __dfault, char * __to) const [protected], [virtual]

Narrow char_type array to char. This virtual function converts each char_type in the range [__lo,__hi) to char using the simplest reasonable transformation and writes the results to the destination array. For any element in the input that cannot be converted, __dfault is used instead.

do_narrow() is a hook for a derived facet to change the behavior of narrowing. do_narrow() must always return the same result for the same input.

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.
__dfault Char to use if conversion fails.
__to Pointer to the destination array.

Returns:

__hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_scan_is (mask __m, const char_type * __lo, const char_type * __hi) const [protected], [virtual]

Find char_type matching mask. This function searches for and returns the first char_type c in [__lo,__hi) for which is(__m,c) is true.

do_scan_is() is a hook for a derived facet to change the behavior of match searching. do_is() must always return the same result for the same input.

Parameters:

__m The mask to compare against.
__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

Pointer to a matching char_type if found, else __hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_scan_not (mask __m, const char_type * __lo, const char_type * __hi) const [protected], [virtual]

Find char_type not matching mask. This function searches for and returns a pointer to the first char_type c of [lo,hi) for which is(m,c) is false.

do_scan_is() is a hook for a derived facet to change the behavior of match searching. do_is() must always return the same result for the same input.

Parameters:

__m The mask to compare against.
__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

Pointer to a non-matching char_type if found, else __hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual char_type std::ctype< _CharT >::do_tolower (char_type __c) const [protected], [virtual]

Convert to lowercase. This virtual function converts the argument to lowercase if possible. If not possible (for example, '2'), returns the argument.

do_tolower() is a hook for a derived facet to change the behavior of lowercasing. do_tolower() must always return the same result for the same input.

Parameters:

__c The char_type to convert.

Returns:

The lowercase char_type if convertible, else __c.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_tolower (char_type * __lo, const char_type * __hi) const [protected], [virtual]

Convert array to lowercase. This virtual function converts each char_type in the range [__lo,__hi) to lowercase if possible. Other elements remain untouched.

do_tolower() is a hook for a derived facet to change the behavior of lowercasing. do_tolower() must always return the same result for the same input.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

__hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual char_type std::ctype< _CharT >::do_toupper (char_type __c) const [protected], [virtual]

Convert to uppercase. This virtual function converts the char_type argument to uppercase if possible. If not possible (for example, '2'), returns the argument.

do_toupper() is a hook for a derived facet to change the behavior of uppercasing. do_toupper() must always return the same result for the same input.

Parameters:

__c The char_type to convert.

Returns:

The uppercase char_type if convertible, else __c.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char_type* std::ctype< _CharT >::do_toupper (char_type * __lo, const char_type * __hi) const [protected], [virtual]

Convert array to uppercase. This virtual function converts each char_type in the range [__lo,__hi) to uppercase if possible. Other elements remain untouched.

do_toupper() is a hook for a derived facet to change the behavior of uppercasing. do_toupper() must always return the same result for the same input.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

__hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual char_type std::ctype< _CharT >::do_widen (char __c) const [protected], [virtual]

Widen char. This virtual function converts the char to char_type using the simplest reasonable transformation.

do_widen() is a hook for a derived facet to change the behavior of widening. do_widen() must always return the same result for the same input.

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__c The char to convert.

Returns:

The converted char_type

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> virtual const char* std::ctype< _CharT >::do_widen (const char * __lo, const char * __hi, char_type * __to) const [protected], [virtual]

Widen char array. This function converts each char in the input to char_type using the simplest reasonable transformation.

do_widen() is a hook for a derived facet to change the behavior of widening. do_widen() must always return the same result for the same input.

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__lo Pointer to start range.
__hi Pointer to end of range.
__to Pointer to the destination array.

Returns:

__hi.

Implements std::__ctype_abstract_base< _CharT >.

template<typename _CharT> bool std::__ctype_abstract_base< _CharT >::is (mask __m, char_type __c) const [inline], [inherited]

Test char_type classification. This function finds a mask M for __c and compares it to mask __m. It does so by returning the value of ctype<char_type>::do_is().

Parameters:

__c The char_type to compare the mask of.
__m The mask to compare against.

Returns:

(M & __m) != 0.

Definition at line 169 of file locale_facets.h.

Referenced by std::time_get< _CharT, _InIter >::get(), std::ctype< char >::is(), std::isalnum(), std::isalpha(), std::isblank(), std::iscntrl(), std::isdigit(), std::isgraph(), std::islower(), std::isprint(), std::ispunct(), std::isspace(), std::isupper(), std::isxdigit(), and std::basic_istream< _CharT, _Traits >::sentry::sentry().

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::is (const char_type * __lo, const char_type * __hi, mask * __vec) const [inline], [inherited]

Return a mask array. This function finds the mask for each char_type in the range [lo,hi) and successively writes it to vec. vec must have as many elements as the char array. It does so by returning the value of ctype<char_type>::do_is().

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.
__vec Pointer to an array of mask storage.

Returns:

__hi.

Definition at line 186 of file locale_facets.h.

template<typename _CharT> char std::__ctype_abstract_base< _CharT >::narrow (char_type __c, char __dfault) const [inline], [inherited]

Narrow char_type to char. This function converts the char_type to char using the simplest reasonable transformation. If the conversion fails, dfault is returned instead. It does so by returning ctype<char_type>::do_narrow(__c).

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__c The char_type to convert.
__dfault Char to return if conversion fails.

Returns:

The converted char.

Definition at line 331 of file locale_facets.h.

Referenced by std::time_get< _CharT, _InIter >::do_date_order(), std::time_get< _CharT, _InIter >::get(), and std::time_put< _CharT, _OutIter >::put().

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::narrow (const char_type * __lo, const char_type * __hi, char __dfault, char * __to) const [inline], [inherited]

Narrow array to char array. This function converts each char_type in the input to char using the simplest reasonable transformation and writes the results to the destination array. For any char_type in the input that cannot be converted, dfault is used instead. It does so by returning ctype<char_type>::do_narrow(__lo, __hi, __dfault, __to).

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.
__dfault Char to use if conversion fails.
__to Pointer to the destination array.

Returns:

__hi.

Definition at line 353 of file locale_facets.h.

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::scan_is (mask __m, const char_type * __lo, const char_type * __hi) const [inline], [inherited]

Find char_type matching a mask. This function searches for and returns the first char_type c in [lo,hi) for which is(m,c) is true. It does so by returning ctype<char_type>::do_scan_is().

Parameters:

__m The mask to compare against.
__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

Pointer to matching char_type if found, else __hi.

Definition at line 202 of file locale_facets.h.

Referenced by std::ctype< char >::is().

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::scan_not (mask __m, const char_type * __lo, const char_type * __hi) const [inline], [inherited]

Find char_type not matching a mask. This function searches for and returns the first char_type c in [lo,hi) for which is(m,c) is false. It does so by returning ctype<char_type>::do_scan_not().

Parameters:

__m The mask to compare against.
__lo Pointer to first char in range.
__hi Pointer to end of range.

Returns:

Pointer to non-matching char if found, else __hi.

Definition at line 218 of file locale_facets.h.

Referenced by std::money_get< _CharT, _InIter >::do_get(), and std::ctype< char >::scan_is().

template<typename _CharT> char_type std::__ctype_abstract_base< _CharT >::tolower (char_type __c) const [inline], [inherited]

Convert to lowercase. This function converts the argument to lowercase if possible. If not possible (for example, '2'), returns the argument. It does so by returning ctype<char_type>::do_tolower(c).

Parameters:

__c The char_type to convert.

Returns:

The lowercase char_type if convertible, else __c.

Definition at line 261 of file locale_facets.h.

Referenced by std::time_get< _CharT, _InIter >::get(), and std::tolower().

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::tolower (char_type * __lo, const char_type * __hi) const [inline], [inherited]

Convert array to lowercase. This function converts each char_type in the range [__lo,__hi) to lowercase if possible. Other elements remain untouched. It does so by returning ctype<char_type>:: do_tolower(__lo, __hi).

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

__hi.

Definition at line 276 of file locale_facets.h.

template<typename _CharT> char_type std::__ctype_abstract_base< _CharT >::toupper (char_type __c) const [inline], [inherited]

Convert to uppercase. This function converts the argument to uppercase if possible. If not possible (for example, '2'), returns the argument. It does so by returning ctype<char_type>::do_toupper().

Parameters:

__c The char_type to convert.

Returns:

The uppercase char_type if convertible, else __c.

Definition at line 232 of file locale_facets.h.

Referenced by std::time_get< _CharT, _InIter >::do_date_order(), std::time_get< _CharT, _InIter >::get(), and std::toupper().

template<typename _CharT> const char_type* std::__ctype_abstract_base< _CharT >::toupper (char_type * __lo, const char_type * __hi) const [inline], [inherited]

Convert array to uppercase. This function converts each char_type in the range [lo,hi) to uppercase if possible. Other elements remain untouched. It does so by returning ctype<char_type>:: do_toupper(lo, hi).

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.

Returns:

__hi.

Definition at line 247 of file locale_facets.h.

template<typename _CharT> char_type std::__ctype_abstract_base< _CharT >::widen (char __c) const [inline], [inherited]

Widen char to char_type. This function converts the char argument to char_type using the simplest reasonable transformation. It does so by returning ctype<char_type>::do_widen(c).

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__c The char to convert.

Returns:

The converted char_type.

Definition at line 293 of file locale_facets.h.

Referenced by std::time_get< _CharT, _InIter >::do_get(), std::money_get< _CharT, _InIter >::do_get(), std::time_put< _CharT, _OutIter >::do_put(), and std::money_put< _CharT, _OutIter >::do_put().

template<typename _CharT> const char* std::__ctype_abstract_base< _CharT >::widen (const char * __lo, const char * __hi, char_type * __to) const [inline], [inherited]

Widen array to char_type. This function converts each char in the input to char_type using the simplest reasonable transformation. It does so by returning ctype<char_type>::do_widen(c).

Note: this is not what you want for codepage conversions. See codecvt for that.

Parameters:

__lo Pointer to start of range.
__hi Pointer to end of range.
__to Pointer to the destination array.

Returns:

__hi.

Definition at line 312 of file locale_facets.h.

Member Data Documentation

template<typename _CharT> locale::id std::ctype< _CharT >::id [static]

The facet id for ctype<char_type>

Definition at line 620 of file locale_facets.h.

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Fri Sep 16 2016 libstdc++