std::isdigit(std::locale) - cppreference.com (original) (raw)
| | | | | --------------------------------------------------------------------- | | | | template< class CharT > bool isdigit( CharT ch, const locale& loc ); | | |
Checks if the given character is classified as a digit by the given locale's std::ctype facet.
[edit] Parameters
| ch | - | character |
|---|---|---|
| loc | - | locale |
[edit] Return value
Returns true if the character is classified as a digit, false otherwise.
[edit] Possible implementation
[edit] Example
#include #include #include #include struct jdigit_ctype : std::ctype { std::unordered_set 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