[locale.collate.general] (original) (raw)

28 Text processing library [text]

28.3 Localization library [localization]

28.3.4 Standard locale categories [locale.categories]

28.3.4.5 The collate category [category.collate]

28.3.4.5.1 Class template collate [locale.collate]

28.3.4.5.1.1 General [locale.collate.general]

namespace std { template<class charT> class collate : public locale::facet { public: using char_type = charT;using string_type = basic_string<charT>;explicit collate(size_t refs = 0);int compare(const charT* low1, const charT* high1,const charT* low2, const charT* high2) const; string_type transform(const charT* low, const charT* high) const;long hash(const charT* low, const charT* high) const;static locale::id id;protected: ~collate();virtual int do_compare(const charT* low1, const charT* high1,const charT* low2, const charT* high2) const;virtual string_type do_transform(const charT* low, const charT* high) const;virtual long do_hash (const charT* low, const charT* high) const;};}

The class collate<charT> provides features for use in the collation (comparison) and hashing of strings.

A locale member function template, operator(), uses the collate facet to allow a locale to act directly as the predicate argument for standard algorithms ([algorithms]) and containers operating on strings.

The specializations required in Table 89 ([locale.category]), namely collate<char> and collate<wchar_t>, apply lexicographical ordering ([alg.lex.comparison]).

Each function compares a string of characters *pin the range [low, high).