std::isdigit(std::locale)
From cppreference.com
| Defined in header <locale>
|
||
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.
Parameters
| ch | - | character |
| loc | - | locale |
Return value
Returns true if the character is classified as a digit, false otherwise.
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);
}
|
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
See also
| checks if a character is a digit (function) | |
| checks if a wide character is a digit (function) |
