std::locale::locale
Defined in header <locale> |
||
---|---|---|
(1) | ||
locale() throw(); |
(until C++11) | |
locale() noexcept; |
(since C++11) | |
(2) | ||
locale( const locale& other ) throw(); |
(until C++11) | |
locale( const locale& other ) noexcept; |
(since C++11) | |
explicit locale( const char* std_name ); |
(3) | |
explicit locale( const std::string& std_name ); |
(4) | (since C++11) |
locale( const locale& other, const char* std_name, category cat ); |
(5) | |
locale( const locale& other, const std::string& std_name, category cat ); |
(6) | (since C++11) |
template< class Facet > locale( const locale& other, Facet* f ); |
(7) | |
locale( const locale& other, const locale& one, category cat ); |
(8) |
Contstructs a new locale object.
1) Default constructor. Constructs a copy of the global C++ locale, which is the locale most recently used as the argument to
std::locale::global
or a copy of
std::locale::classic
if no call to
std::locale::global
has been made.
2) Copy constructor. Constructs a copy of
other
.
3-4) Constructs a copy of the system locale with specified
std_name
(such as "C", or "POSIX", or "en_US.UTF-8", or "English_US.1251"), if such locale is supported by the operating system. The locale constructed in this manner has a name.
5-6) Constructs a copy of
other
except for all the facets identified by the
cat
argument, which are copied from the system locale identified by its
std_name
. The locale constructed in this manner has a name if and only if
other
has a name.
7) Constructs a copy of
other
except for the facet of type
Facet
(typically deduced from the type of the argument) which is installed from the argument
facet
. If
facet
is a null pointer, the constructed locale is a full copy of
other
. The locale constructed in this manner has no name.
8) Constructs a copy of
other
except for all the facets identified by the
cat
argument, which are copied from
one
. If both
other
and
one
have names, then the resulting locale also has a name.
Parameters
other | - | another locale to copy |
std_name | - | name of the system locale to use |
f | - | pointer to a facet to merge with other |
cat | - | the locale category used to identify the facets to merge with other |
one | - | another locale to take facets from |
Exceptions
3,5)
std::runtime_error
if the operating system has no locale named
std_name
or if
std_name
is a null pointer.
7,8) May throw implementation-defined exceptions.
Notes
Overload 7 is typically called with its second argument, f
, obtained directly from a new-expression: the locale is responsible for calling the matching delete
from its own destructor.
Example
#include <codecvt> #include <iostream> #include <locale> std::ostream& operator<< (std::ostream& os, std::locale const& loc) { if (loc.name().length() <= 80) { return os << loc.name() << '\n'; } for (const auto c : loc.name()) { c != ';' ? os << c : os << "\n "; } return os << '\n'; } int main() { std::locale l1; // l1 is a copy of the classic "C" locale std::locale l2("en_US.UTF-8"); // l2 is a unicode locale std::locale l3(l1, l2, std::locale::ctype); // l3 is "C" except for ctype, which is unicode std::locale l4(l1, new std::codecvt_utf8<wchar_t>); // l4 is "C" except for codecvt std::cout << "Locale names:\n" << "l1: " << l1 << "l2: " << l2 << "l3: " << l3 << "l4: " << l4; }
Possible output:
Locale names: l1: C l2: en_US.UTF-8 l3: LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=C LC_COLLATE=C LC_MONETARY=C LC_MESSAGES=C LC_PAPER=C LC_NAME=C LC_ADDRESS=C LC_TELEPHONE=C LC_MEASUREMENT=C LC_IDENTIFICATION=C l4: *
See also
destructs the locale and the facets whose reference count becomes zero (public member function) |
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