std::locale::id(3)

💖 std::locale::id — the group chat lore 💖

okay bestie so this is std::locale::id(3), from the Library Functions Manual (yes that's the manual name, we're being fancy today ✨). It's a C++ thing from libstdc++ and it's lowkey the reason facets can find themselves in a locale. Let's get into it 🫶

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🌸 NAME 🌸

std::locale::id — the Facet ID class. that's it, that's the name, she's iconic 👑

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✨ SYNOPSIS ✨

#include <locale>

🎀 Public Member Functions 🎀

• id () — Constructor. the whole personality tbh.
• size_t _M_id () const throw () — yeah she's private-ish energy but here she is, listed plain as day.

🦋 Friends 🦋

• template<typename _Facet> const _Facet * __try_use_facet (const locale &__loc) — a friend, a real one.
• template<typename _Facet> bool has_facet (const locale &__loc) throw () — Test for the presence of a facet. the vibe check function fr fr.
• class locale — friend of the house 💅
• class locale::_Impl — also friend of the house 💅
• template<typename _Facet> const _Facet & use_facet (const locale &__loc) — Return a facet. the actual getting-it function.

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🌈 Detailed Description 🌈

Facet ID class. yes bestie, that's the whole description up top, we keep it real.

The ID class provides facets with an index used to identify them. Every facet class must define a public static member locale::id, or be derived from a facet that provides this member — otherwise the facet cannot be used in a locale. (like, at all. no index, no entry, no invitation to the function party 😭). The locale::id ensures that each class type gets a unique identifier. periodt. 💖

not me stressing: if you forget your static locale::id member, your facet is just out here, unable to be used in a locale. define it. bestie. please. 🙈

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👑 Constructor & Destructor Documentation 👑

🧚 std::locale::id::id () [inline]

Constructor. she constructs. that's the job. 💅

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💜 Friends And Related Symbol Documentation 💜

⭐ template<typename _Facet> bool has_facet (const locale & __loc) [friend]

Test for the presence of a facet. has_facet tests the locale argument for the presence of the facet type provided as the template parameter. Facets derived from the facet parameter will also return true. (derived facets count too, we love inclusivity 🌸)

Template Parameters

• _Facet — The facet type to test the presence of.

Parameters

• __loc — The locale to test.

Returns

true if __loc contains a facet of type _Facet, else false. simple as that, no cap ✨

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💖 template<typename _Facet> const _Facet & use_facet (const locale & __loc) [friend]

Return a facet. use_facet looks for and returns a reference to a facet of type Facet where Facet is the template parameter. If has_facet(locale) is true, there is a suitable facet to return. It throws std::bad_cast if the locale doesn't contain a facet of type Facet. 💀

Template Parameters

• _Facet — The facet type to access.

Parameters

• __loc — The locale to use.

Returns

Reference to facet of type Facet.

Exceptions

• std::bad_cast if __loc doesn't contain a facet of type _Facet.

reminder bestie: if has_facet says no and you call use_facet anyway, that's a std::bad_cast coming for you. check first, slay later 🎀

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🍓 Author 🍓

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

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and that's the whole page, mwah 💋 — this was libstdc++, std::locale::id(3), brought to you by the Library Functions Manual, signed, sealed, delivered, no date on the footer so we're just gonna say: it's giving timeless. byeee 🦋💖✨