std::has_facet
From cppreference.com
Defined in header
<locale>
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template< class Facet >
bool has_facet( const locale& loc ); |
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Checks if the locale loc
implements the facet Facet
.
Contents |
[edit] Parameters
loc | - | the locale object to query |
[edit] Return value
Returns true if the facet Facet
was installed in the locale loc
, false otherwise.
[edit] Exceptions
(none) | (until C++11) |
noexcept specification:
noexcept |
(since C++11) |
[edit] Example
Run this code
#include <iostream> #include <locale> // minimal custom facet struct myfacet : public std::locale::facet { static std::locale::id id; }; std::locale::id myfacet::id; int main() { // loc is a "C" locale with myfacet added std::locale loc(std::locale::classic(), new myfacet); std::cout << std::boolalpha << "Can loc classify chars? " << std::has_facet<std::ctype<char>>(loc) << '\n' << "Can loc classify char32_t? " << std::has_facet<std::ctype<char32_t>>(loc) << '\n' << "Does loc implement myfacet? " << std::has_facet<myfacet>(loc) << '\n'; }
Output:
Can loc classify chars? true Can loc classify char32_t? false Does loc implement myfacet? true
[edit] See also
set of polymorphic facets that encapsulate cultural differences (class) |
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obtains a facet from a locale (function template) |