| Localization library | |||||||||||||||||||||||||
| Regular expressions library(C++11) | |||||||||||||||||||||||||
| Formatting library(C++20) | |||||||||||||||||||||||||
| Null-terminated sequence utilities | |||||||||||||||||||||||||
| Byte strings | |||||||||||||||||||||||||
| Multibyte strings | |||||||||||||||||||||||||
| Wide strings | |||||||||||||||||||||||||
| Primitive numeric conversions | |||||||||||||||||||||||||
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| Text encoding identifications | |||||||||||||||||||||||||
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| Member types | ||||
locale::id | ||||
| Member functions | ||||
(C++26) | ||||
(until C++20) | ||||
| Static member functions | ||||
Defined in header <locale> | ||
class locale::id; | ||
The classstd::locale::id provides implementation-specific identification of a locale facet. Eachfacet has a public static member namedid of typestd::locale::id and eachstd::locale object maintains a list of facets it implements, indexed by theirids.
Facets with the sameid belong to the same facet category and replace each other when added to a locale object.
| constructs a new id (public member function) | |
operator= | copy assignment operator is deleted (public member function) |
The following example shows how to construct a minimal custom facet.
#include <iostream>#include <locale> struct myfacet:std::locale::facet{ myfacet(std::size_t refs=0): facet(refs){}static::std::locale::id id;}; std::locale::id myfacet::id; int main(){std::locale myloc(std::locale(), new myfacet);std::cout<<"has_facet<myfacet>(myloc) returns "<<std::boolalpha<<std::has_facet<myfacet>(myloc)<<'\n';}
Output:
has_facet<myfacet>(myloc) returns true
| the base class for all facet categories: each facet of any category is derived from this type (class)[edit] |
