STD::__CTYPE_ABSTRACT_BASE(3)

✨ straight out of the Library Functions Manual, section 3 — this is std::__ctype_abstract_base< _CharT >(3) and she's a whole mood 💅

💖 NAME 💖

std::__ctype_abstract_base< _CharT > — the common base for the ctype facet. Like, the shared ancestor energy. The blueprint all the ctype girlies inherit from. 👑

---

🌸 SYNOPSIS 🌸

#include <locale>

Inherits std::locale::facet, and std::ctype_base.

Inherited by std::mask< _CharT >, std::ctype< char >, and std::ctype< _CharT >. So yeah, she's the mom of the family, no cap. 🫶

✨ Public Types ✨

• typedef const int * __to_type
• typedef _CharT char_type — typedef for the template parameter, iconic behaviour honestly.
• typedef unsigned short mask

🦋 Public Member Functions 🦋

• const char_type * is (const char_type *__lo, const char_type *__hi, mask *__vec) const — return a mask array.
• bool is (mask __m, char_type __c) const — test a char_type classification.
• char narrow (char_type __c, char __dfault) const — narrow char_type down to char.
• const char_type * narrow (const char_type *__lo, const char_type *__hi, char __dfault, char *__to) const — narrow an array down to a char array.
• const char_type * scan_is (mask __m, const char_type *__lo, const char_type *__hi) const — find a char_type matching a mask.
• const char_type * scan_not (mask __m, const char_type *__lo, const char_type *__hi) const — find a char_type that does not match a mask.
• const char_type * tolower (char_type *__lo, const char_type *__hi) const — convert an array to lowercase.
• char_type tolower (char_type __c) const — convert to lowercase.
• const char_type * toupper (char_type *__lo, const char_type *__hi) const — convert an array to uppercase.
• char_type toupper (char_type __c) const — convert to uppercase.
• char_type widen (char __c) const — widen a char to char_type.
• const char * widen (const char *__lo, const char *__hi, char_type *__to) const — widen an 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 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 🎀

• __ctype_abstract_base (size_t __refs=0)
• virtual const char_type * do_is (const char_type *__lo, const char_type *__hi, mask *__vec) const =0 — return a mask array.
• virtual bool do_is (mask __m, char_type __c) const =0 — test a char_type classification.
• virtual char do_narrow (char_type __c, char __dfault) const =0 — narrow char_type to char.
• virtual const char_type * do_narrow (const char_type *__lo, const char_type *__hi, char __dfault, char *__to) const =0 — narrow a char_type array to char.
• virtual const char_type * do_scan_is (mask __m, const char_type *__lo, const char_type *__hi) const =0 — find a char_type matching a mask.
• virtual const char_type * do_scan_not (mask __m, const char_type *__lo, const char_type *__hi) const =0 — find a char_type not matching a mask.
• virtual const char_type * do_tolower (char_type *__lo, const char_type *__hi) const =0 — convert an array to lowercase.
• virtual char_type do_tolower (char_type __c) const =0 — convert to lowercase.
• virtual const char_type * do_toupper (char_type *__lo, const char_type *__hi) const =0 — convert an array to uppercase.
• virtual char_type do_toupper (char_type __c) const =0 — convert to uppercase.
• virtual char_type do_widen (char __c) const =0 — widen a char.
• virtual const char * do_widen (const char *__lo, const char *__hi, char_type *__to) const =0 — widen a 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_abstract_base< _CharT >

Common base for ctype facet.

Okay so here's the tea ☕ — this template class hands you actual implementations of the public functions, and those implementations just forward everything to the protected virtual functions. Middle-manager behaviour, but make it couture. 💅

And this template also provides abstract stubs for those protected virtual functions. So she's giving "here's the shape of it, now you do the work" — very main character. ✨

---

🧚 Member Typedef Documentation 🧚

template<typename _CharT> typedef _CharT std::__ctype_abstract_base< _CharT >::char_type

Typedef for the template parameter. That's it, that's the whole job. 🎀

---

💖 Member Function Documentation 💖

do_is (the array one) 🌸

template<typename _CharT> virtual const char_type *
    std::__ctype_abstract_base< _CharT >::do_is (const char_type * __lo,
    const char_type * __hi, mask * __vec) const [protected],  [pure 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. No skipping, bestie, the storage has to match. 😭

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. Consistency queen. 👑

Parameters

• __lo — pointer to start of range.
• __hi — pointer to end of range.
• __vec — pointer to an array of mask storage.

Returns

__hi.

Implemented in std::ctype< _CharT >, and std::mask< _CharT >.

---

do_is (the one-mask one) 🦋

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

Test char_type classification. This function finds a mask M for c and compares it to mask m. It's giving compare-and-contrast, but for characters. ✨

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. Same input, same output, periodt. 💅

Parameters

• __c — the char_type to find the mask of.
• __m — the mask to compare against.

Returns

(M & __m) != 0.

Implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >.

Referenced by std::mask< _CharT >::is(), and std::mask< _CharT >::is().

---

do_narrow (single char) 🎀

template<typename _CharT> virtual char std::__ctype_abstract_base< _CharT
    >::do_narrow (char_type __c, char __dfault) const [protected],  [pure
    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. Fallback friend behaviour, we love her. 🫶

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. Do not come crying to do_narrow about codepages, she will not help you. 😭

Parameters

• __c — the char_type to convert.
• __dfault — char to return if conversion fails.

Returns

The converted char.

Implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >.

Referenced by std::mask< _CharT >::narrow(), and std::mask< _CharT >::narrow().

---

do_narrow (the array one) 🌈

template<typename _CharT> virtual const char_type *
    std::__ctype_abstract_base< _CharT >::do_narrow (const char_type * __lo,
    const char_type * __hi, char __dfault, char * __to) const [protected],
    [pure 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. One flop in the group and __dfault catches them, iconic. 💅

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. Seriously. Not this one. 🙈

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.

Implemented in std::ctype< _CharT >, and std::mask< _CharT >.

---

do_scan_is 🔥

template<typename _CharT> virtual const char_type *
    std::__ctype_abstract_base< _CharT >::do_scan_is (mask __m, const
    char_type * __lo, const char_type * __hi) const [protected],  [pure
    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. First match wins, no second-guessing. ⭐

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.

Implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >.

Referenced by std::mask< _CharT >::scan_is().

---

do_scan_not 💀

template<typename _CharT> virtual const char_type *
    std::__ctype_abstract_base< _CharT >::do_scan_not (mask __m, const
    char_type * __lo, const char_type * __hi) const [protected],  [pure
    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. The contrarian of the group chat, and honestly? Valid. 🙈

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.

Implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >.

Referenced by std::mask< _CharT >::scan_not().

---

do_tolower (array edition) 🍓

template<typename _CharT> virtual const char_type *
    std::__ctype_abstract_base< _CharT >::do_tolower (char_type * __lo,
    const char_type * __hi) const [protected],  [pure 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. Not everything needs a glow-down and she respects that. 🎀

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.

Implemented in std::ctype< _CharT >, and std::mask< _CharT >.

---

do_tolower (single char edition) 💜

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

Convert to lowercase. This virtual function converts the argument to lowercase if possible. If not possible (for example, '2'), returns the argument. '2' said "I'm perfect actually" and honestly, correct. 💅

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.

---

💅 oh and btw, the previous one was implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >. Also referenced by std::mask< _CharT >::tolower(), and std::mask< _CharT >::tolower() — not the double mention, but we move 💀.

---

do_toupper — the array glow-up ✨

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

Convert array to uppercase, bestie. This virtual function converts each char_type in the range [__lo,__hi) to uppercase if possible. Other elements stay untouched, no cap.

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

• __lo — pointer to start of range.
• __hi — pointer to end of range.

Returns: __hi.

💖 implemented in std::ctype< _CharT >, and std::mask< _CharT >.

---

do_toupper — the single char serve 🦋

template<typename _CharT> virtual char_type std::__ctype_abstract_base< _CharT >::do_toupper (char_type __c) const [protected], [pure 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. It's giving "I tried my best".

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.

• __c — the char_type to convert.

Returns: the uppercase char_type if convertible, else __c.

💅 implemented in std::ctype< _CharT >, std::ctype< wchar_t >, and std::mask< _CharT >. referenced by std::mask< _CharT >::toupper(), and std::mask< _CharT >::toupper() — again with the double, but ok.

---

do_widen — char edition 🌸

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

• __c — the char to convert.

Returns: the converted char_type.

💜 implemented in std::ctype< _CharT >, std::ctype< char >, std::ctype< wchar_t >, and std::mask< _CharT >. referenced by std::mask< _CharT >::widen(), and std::mask< _CharT >::widen().

---

do_widen — array edition 🌈

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

• __lo — pointer to start range.
• __hi — pointer to end of range.
• __to — pointer to the destination array.

Returns: __hi.

💖 implemented in std::ctype< _CharT >, and std::mask< _CharT >.

---

is — mask array vibes 🎀

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

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().

• __lo — pointer to start of range.
• __hi — pointer to end of range.
• __vec — pointer to an array of mask storage.

Returns: __hi.

---

is — single char check 💅

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

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().

• __c — the char_type to compare the mask of.
• __m — the mask to compare against.

Returns: (M & __m) != 0.

🔥 referenced by std::time_get< _CharT, _InIter >::get().

---

narrow — single char 🧚

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

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.

• __c — the char_type to convert.
• __dfault — char to return if conversion fails.

Returns: the converted char.

💖 referenced by std::time_get< _CharT, _InIter >::do_get_year(), std::time_get< _CharT, _InIter >::get(), and std::time_put< _CharT, _OutIter >::put().

---

narrow — array 🦋

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]

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.

• __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.

---

scan_is — find matching mask ✨

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]

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().

• __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.

---

scan_not — find non-matching mask 🌸

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]

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().

• __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.

---

tolower — array glow-down 💜

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

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).

• __lo — pointer to start of range.
• __hi — pointer to end of range.

Returns: __hi.

---

tolower — single char 💅

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

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).

• __c — the char_type to convert.

Returns: the lowercase char_type if convertible, else __c.

🔥 referenced by std::time_get< _CharT, _InIter >::get().

---

toupper — array glow-up 🎀

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

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).

• __lo — pointer to start of range.
• __hi — pointer to end of range.

Returns: __hi.

---

toupper — single char ✨

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

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().

• __c — the char_type to convert.

Returns: the uppercase char_type if convertible, else __c.

🔥 referenced by std::time_get< _CharT, _InIter >::get().

---

widen — single char 🌈

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

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.

• __c — the char to convert.

Returns: the converted char_type.

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

---

widen — array 🦋

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

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.

• __lo — pointer to start of range.
• __hi — pointer to end of range.
• __to — pointer to the destination array.

Returns: __hi.

---

👑 AUTHOR 👑

Generated automatically by Doxygen for libstdc++ from the source code.

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💖 and that's the whole vibe, bestie! this manual page is from libstdc++ — std::__cty...< _CharT >(3) — periodt. slay! ✨