std::numpunct
| Defined in header <locale>
|
||
| template< class CharT > class numpunct; |
||
The facet std::numpunct encapsulates numeric punctuation preferences. Stream I/O operations use std::numpunct through std::num_get and std::num_put for parsing numeric input and formatting numeric output.
The numbers that are supported by std::numpunct have the format described below. Here digit represents the radix set specified by the fmtflags argument value, thousands-sep and decimal-point are the results of thousands_sep() and decimal_point() functions respectively. The format of integer values is as follows:
integer ::= [sign] units sign ::= plusminus plusminus ::= '+' | '-' units ::= digits [thousands-sep units] digits ::= digit [digits]
The number of digits between the thousand-seps (maximum size of digits) is specified by the result of grouping().
The format of floating-point values is as follows:
floatval ::= [sign] units [decimal-point [digits]] [e [sign] digits] |
[sign] decimal-point digits [e [sign] digits]
e ::= 'e' | 'E'
Inheritance diagram
Two standalone (locale-independent) specializations are provided by the standard library:
| Defined in header
<locale> | |
| std::numpunct<char> | provides equivalents of the "C" locale preferences |
| std::numpunct<wchar_t> | provides wide character equivalents of the "C" locale preferences |
In addition, every locale object constructed in a C++ program implements its own (locale-specific) versions of these specializations.
Contents |
Member types
| Member type | Definition |
char_type
|
charT
|
string_type
|
std::basic_string<charT> |
Member functions
constructs a new numpunct facet (public member function) | |
destructs a numpunct facet (protected member function) | |
| | |
invokes do_decimal_point (public member function) | |
invokes do_thousands_sep (public member function) | |
invokes do_grouping (public member function) | |
invokes do_truename or do_falsename (public member function) | |
Protected member functions
| [virtual] |
provides the character to use as decimal point (virtual protected member function) |
| [virtual] |
provides the character to use as thousands separator (virtual protected member function) |
| [virtual] |
provides the numbers of digits between each pair of thousands separators (virtual protected member function) |
| [virtual] |
provides the string to use as the name of the boolean true and false (virtual protected member function) |
Member objects
| static std::locale::id id |
id of the locale (public member object) |
Example
The following example changes the string representations of true and false
#include <iostream> #include <locale> struct french_bool : std::numpunct<char> { string_type do_truename() const { return "oui"; } string_type do_falsename() const { return "non"; } }; int main() { std::cout << "default locale: " << std::boolalpha << true << ", " << false << '\n'; std::cout.imbue(std::locale(std::cout.getloc(), new french_bool)); std::cout << "locale with modified numpunct: " << std::boolalpha << true << ", " << false << '\n'; }
Output:
default locale: true, false locale with modified numpunct: oui, non
See also
| creates a numpunct facet for the named locale (class template) |
