std::ctype<CharT>::scan_is, std::ctype<CharT>::do_scan_is
From cppreference.com
| Defined in header <locale>
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| public: const CharT* scan_is( mask m, const CharT* beg, const CharT* end ) const; |
(1) | |
| protected: virtual const CharT* do_scan_is( mask m, const CharT* beg, const CharT* end ) const; |
(2) | |
1) public member function, calls the protected virtual member function
do_scan_is of the most derived class.2) Locates the first character in the character array
[beg, end) that satisfies the classification mask m, that is, the first character c such that is(m, c) would return true.Parameters
| m | - | mask to search for |
| beg | - | pointer to the first character in an array of characters to search |
| end | - | one past the end pointer for the array of characters to search |
Return value
Pointer to the first character in [beg, end) that satisfies the mask, or end if no such character was found.
Example
Run this code
#include <locale> #include <clocale> #include <iostream> #include <iterator> int main() { std::setlocale(LC_ALL, "en_US.utf8"); std::wcout.imbue(std::locale("en_US.utf8")); auto& f = std::use_facet<std::ctype<wchar_t>>(std::wcout.getloc()); // skip until the first letter wchar_t s1[] = L" \t\t\n Кошка"; const wchar_t* p1 = f.scan_is(std::ctype_base::alpha, std::begin(s1), std::end(s1)); std::wcout << "'" << p1 << "'\n"; // skip until the first letter wchar_t s2[] = L"123456789ネプネプ"; const wchar_t* p2 = f.scan_is(std::ctype_base::alpha, std::begin(s2), std::end(s2)); std::wcout << "'" << p2 << "'\n"; }
Output:
'Кошка' 'ネプネプ'
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 152 | C++98 | the effect of do_scan_is mentioned is(m),but is does not have such an overload |
corrected to is(m, c) |
See also
| locates the first character in a sequence that conforms to given classification, using the classification table (public member function of std::ctype<char>) | |
| [virtual] |
locates the first character in a sequence that fails given classification (virtual protected member function) |