std::isdigit(std::locale)
From cppreference.com
| Defined in header <locale>
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| template< class CharT > bool isdigit( CharT ch, const locale& loc ); |
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Checks if the given character is classified as a digit by the given locale's std::ctype facet.
Contents |
[edit] Parameters
| ch | - | character |
| loc | - | locale |
[edit] Return value
Returns true if the character is classified as a digit, false otherwise.
[edit] Possible implementation
template<class CharT> bool isdigit(CharT ch, const std::locale& loc) { return std::use_facet<std::ctype<CharT>>(loc).is(std::ctype_base::digit, ch); } |
[edit] Example
Run this code
#include <iostream> #include <locale> #include <string> #include <unordered_set> struct jdigit_ctype : std::ctype<wchar_t> { std::unordered_set<wchar_t> jdigits{ L'一', L'二', L'三', L'四', L'五', L'六', L'七', L'八', L'九', L'十' }; bool do_is(mask m, char_type c) const override { return (m & digit) && jdigits.contains(c) ? true // Japanese digits will be classified as digits : ctype::do_is(m, c); // leave the rest to the parent class } }; int main() { std::wstring text = L"123一二三１２３"; std::locale loc(std::locale(""), new jdigit_ctype); std::locale::global(std::locale("en_US.utf8")); std::wcout.imbue(std::locale()); for (const wchar_t c : text) if (std::isdigit(c, loc)) std::wcout << c << " is a digit\n"; else std::wcout << c << " is NOT a digit\n"; }
Possible output:
1 is a digit 2 is a digit 3 is a digit 一 is a digit 二 is a digit 三 is a digit １ is NOT a digit ２ is NOT a digit ３ is NOT a digit
[edit] See also
| checks if a character is a digit (function) | |
| checks if a wide character is a digit (function) |
