Difference between revisions of "cpp/locale/locale/combine"
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| − | {{cpp/locale/locale/title | combine}} | + | {{cpp/locale/locale/title|combine}} |
| − | {{cpp/locale/locale/ | + | {{cpp/locale/locale/navbar}} |
| − | {{ddcl | + | {{ddcl| |
template< class Facet > | template< class Facet > | ||
locale combine( const locale& other ) const; | locale combine( const locale& other ) const; | ||
}} | }} | ||
| − | Constructs a locale object which is a copy of {{ | + | Constructs a locale object which is a copy of {{c|*this}} except for the facet of type {{tt|Facet}}, which is copied from {{c|other}}. |
| + | |||
| + | The program is ill-formed if Facet is not a {{rlp|facet#Facet class|facet}} or it is a volatile-qualified facet. | ||
===Return value=== | ===Return value=== | ||
| Line 13: | Line 15: | ||
===Exceptions=== | ===Exceptions=== | ||
| − | {{ | + | {{lc|std::runtime_error}} if {{c|other}} does not implement {{tt|Facet}}. |
===Example=== | ===Example=== | ||
| − | {{example | + | {{example |
| − | + | | | |
| − | + | |code= | |
#include <iostream> | #include <iostream> | ||
#include <locale> | #include <locale> | ||
| Line 26: | Line 28: | ||
const double number = 1000.25; | const double number = 1000.25; | ||
std::cout << "\"C\" locale: " << number << '\n'; | std::cout << "\"C\" locale: " << number << '\n'; | ||
| − | std::locale loc = std::locale().combine<std::numpunct<char>>(std::locale("en_US.UTF8")); | + | std::locale loc = std::locale() |
| + | .combine<std::numpunct<char>>(std::locale("en_US.UTF8")); | ||
std::cout.imbue(loc); | std::cout.imbue(loc); | ||
std::cout << "\"C\" locale with en_US numpunct: " << number << '\n'; | std::cout << "\"C\" locale with en_US numpunct: " << number << '\n'; | ||
} | } | ||
| − | + | |output= | |
"C" locale: 1000.25 | "C" locale: 1000.25 | ||
"C" locale with en_US numpunct: 1,000.25 | "C" locale with en_US numpunct: 1,000.25 | ||
}} | }} | ||
| + | |||
| + | ===Defect reports=== | ||
| + | {{dr list begin}} | ||
| + | {{dr list item|wg=lwg|dr=14|std=C++98|before={{tt|locale::combine}} was non-const|after=made const}} | ||
| + | {{dr list item|wg=lwg|dr=436|std=C++98|before=it was unclear whether {{tt|Facet}} can be cv-qualified|after=it can be const-qualified, but not volatile-qualified}} | ||
| + | {{dr list end}} | ||
===See also=== | ===See also=== | ||
| − | {{ | + | {{dsc begin}} |
| − | {{ | + | {{dsc inc|cpp/locale/locale/dsc locale}} |
| − | {{ | + | {{dsc end}} |
| + | |||
| + | {{langlinks|de|es|fr|it|ja|pt|ru|zh}} | ||
Latest revision as of 22:54, 18 October 2024
| template< class Facet > locale combine( const locale& other ) const; |
||
Constructs a locale object which is a copy of *this except for the facet of type Facet, which is copied from other.
The program is ill-formed if Facet is not a facet or it is a volatile-qualified facet.
Contents |
[edit] Return value
The new, nameless, locale.
[edit] Exceptions
std::runtime_error if other does not implement Facet.
[edit] Example
Run this code
#include <iostream> #include <locale> int main() { const double number = 1000.25; std::cout << "\"C\" locale: " << number << '\n'; std::locale loc = std::locale() .combine<std::numpunct<char>>(std::locale("en_US.UTF8")); std::cout.imbue(loc); std::cout << "\"C\" locale with en_US numpunct: " << number << '\n'; }
Output:
"C" locale: 1000.25 "C" locale with en_US numpunct: 1,000.25
[edit] 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 14 | C++98 | locale::combine was non-const
|
made const |
| LWG 436 | C++98 | it was unclear whether Facet can be cv-qualified
|
it can be const-qualified, but not volatile-qualified |
[edit] See also
| constructs a new locale (public member function) |
