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<locale> functions

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has_facet
isalnum
isalpha
iscntrl
isdigit
isgraph
islower
isprint
ispunct
isspace
isupper
isxdigit
tolower
toupper
use_facet

has_facet

Tests if a particular facet is stored in a specified locale.

template <class Facet>
bool has_facet(const locale& Loc);

Parameters

Loc
The locale to be tested for the presence of a facet.

Return Value

true if the locale has the facet tested for; false if it does not.

Remarks

The template function is useful for checking whether nonmandatory facets are listed in a locale before use_facet is called to avoid the exception that would be thrown if it were not present.

Example

// locale_has_facet.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result = has_facet <ctype<char> > ( loc );
   cout << result << endl;
}

1

isalnum

Tests whether an element in a locale is an alphabetic or a numeric character.

template <class CharType>
bool isalnum(CharType Ch, const locale& Loc)

Parameters

Ch
The alphanumeric element to be tested.

Loc
The locale containing the alphanumeric element to be tested.

Return Value

true if the element tested is alphanumeric; false if it is not.

Example

// locale_isalnum.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isalnum ( 'L', loc);
   bool result2 = isalnum ( '@', loc);
   bool result3 = isalnum ( '3', loc);

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "alphanumeric." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not alphanumeric." << endl;

   if ( result2 )
      cout << "The character '@' in the locale is "
           << "alphanumeric." << endl;
   else
      cout << "The character '@' in the locale is "
           << " not alphanumeric." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "alphanumeric." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not alphanumeric." << endl;
}

The character 'L' in the locale is alphanumeric.
The character '@' in the locale is  not alphanumeric.
The character '3' in the locale is alphanumeric.

isalpha

Tests whether an element in a locale is an alphabetic character.

template <class CharType>
bool isalpha(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the alphabetic element to be tested.

Return Value

true if the element tested is alphabetic; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: alpha, Ch).

Example

// locale_isalpha.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isalpha ( 'L', loc);
   bool result2 = isalpha ( '@', loc);
   bool result3 = isalpha ( '3', loc);

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "alphabetic." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not alphabetic." << endl;

   if ( result2 )
      cout << "The character '@' in the locale is "
           << "alphabetic." << endl;
   else
      cout << "The character '@' in the locale is "
           << " not alphabetic." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "alphabetic." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not alphabetic." << endl;
}

iscntrl

Tests whether an element in a locale is a control character.

template <class CharType>
bool iscntrl(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a control character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: cntrl, Ch).

Example

// locale_iscntrl.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = iscntrl ( 'L', loc );
   bool result2 = iscntrl ( '\n', loc );
   bool result3 = iscntrl ( '\t', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a control character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a control character." << endl;

   if ( result2 )
      cout << "The character-set 'backslash-n' in the locale\n is "
           << "a control character." << endl;
   else
      cout << "The character-set 'backslash-n' in the locale\n is "
           << " not a control character." << endl;

   if ( result3 )
      cout << "The character-set 'backslash-t' in the locale\n is "
           << "a control character." << endl;
   else
      cout << "The character-set 'backslash-n' in the locale \n is "
           << " not a control character." << endl;
}

isdigit

Tests whether an element in a locale is a numeric character.

template <class CharType>
bool isdigit(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a numeric character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: digit, Ch).

Example

// locale_is_digit.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isdigit ( 'L', loc );
   bool result2 = isdigit ( '@', loc );
   bool result3 = isdigit ( '3', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a numeric character." << endl;

   if ( result2 )
      cout << "The character '@' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character '@' in the locale is "
           << " not a numeric character." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not a numeric character." << endl;
}

isgraph

Tests whether an element in a locale is an alphanumeric or punctuation character.

template <class CharType>
bool isgraph(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is an alphanumeric or a punctuation character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: graph, Ch).

Example

// locale_is_graph.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isgraph ( 'L', loc );
   bool result2 = isgraph ( '\t', loc );
   bool result3 = isgraph ( '.', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is\n "
           << "an alphanumeric or punctuation character." << endl;
   else
      cout << "The character 'L' in the locale is\n "
           << " not an alphanumeric or punctuation character." << endl;

   if ( result2 )
      cout << "The character 'backslash-t' in the locale is\n "
           << "an alphanumeric or punctuation character." << endl;
   else
      cout << "The character 'backslash-t' in the locale is\n "
           << "not an alphanumeric or punctuation character." << endl;

   if ( result3 )
      cout << "The character '.' in the locale is\n "
           << "an alphanumeric or punctuation character." << endl;
   else
      cout << "The character '.' in the locale is\n "
           << " not an alphanumeric or punctuation character." << endl;
}

islower

Tests whether an element in a locale is lower case.

template <class CharType>
bool islower(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a lowercase character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: lower, Ch).

Example

// locale_islower.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = islower ( 'L', loc );
   bool result2 = islower ( 'n', loc );
   bool result3 = islower ( '3', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a lowercase character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a lowercase character." << endl;

   if ( result2 )
      cout << "The character 'n' in the locale is "
           << "a lowercase character." << endl;
   else
      cout << "The character 'n' in the locale is "
           << " not a lowercase character." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "a lowercase character." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not a lowercase character." << endl;
}

isprint

Tests whether an element in a locale is a printable character.

template <class CharType>
bool isprint(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a printable; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: print, Ch).

Example

// locale_isprint.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
using namespace std;

int main( )
{
   locale loc ( "German_Germany" );

   bool result1 = isprint ( 'L', loc );
   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a printable character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a printable character." << endl;

   bool result2 = isprint( '\t', loc );
   if ( result2 )
      cout << "The character 'backslash-t' in the locale is "
           << "a printable character." << endl;
   else
      cout << "The character 'backslash-t' in the locale is "
           << " not a printable character." << endl;

   bool result3 = isprint( '\n', loc );
   if ( result3 )
      cout << "The character 'backslash-n' in the locale is "
           << "a printable character." << endl;
   else
      cout << "The character 'backslash-n' in the locale is "
           << " not a printable character." << endl;
}

ispunct

Tests whether an element in a locale is a punctuation character.

template <class CharType>
bool ispunct(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a punctuation character; false if it is not.

Remarks

The template function returns use_facet<ctype< CharType> >( Loc). is( ctype< CharType>:: punct, Ch).

Example

// locale_ispunct.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = ispunct ( 'L', loc );
   bool result2 = ispunct ( ';', loc );
   bool result3 = ispunct ( '*', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a punctuation character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a punctuation character." << endl;

   if ( result2 )
      cout << "The character ';' in the locale is "
           << "a punctuation character." << endl;
   else
      cout << "The character ';' in the locale is "
           << " not a punctuation character." << endl;

   if ( result3 )
      cout << "The character '*' in the locale is "
           << "a punctuation character." << endl;
   else
      cout << "The character '*' in the locale is "
           << " not a punctuation character." << endl;
}

isspace

Tests whether an element in a locale is a whitespace character.

template <class CharType>
bool isspace(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a whitespace character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: space, Ch).

Example

// locale_isspace.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isspace ( 'L', loc );
   bool result2 = isspace ( '\n', loc );
   bool result3 = isspace ( ' ', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a whitespace character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a whitespace character." << endl;

   if ( result2 )
      cout << "The character 'backslash-n' in the locale is "
           << "a whitespace character." << endl;
   else
      cout << "The character 'backslash-n' in the locale is "
           << " not a whitespace character." << endl;

   if ( result3 )
      cout << "The character ' ' in the locale is "
           << "a whitespace character." << endl;
   else
      cout << "The character ' ' in the locale is "
           << " not a whitespace character." << endl;
}

isupper

Tests whether an element in a locale is in upper case.

template <class CharType>
bool isupper(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is an uppercase character; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: upper, Ch).

Example

// locale_isupper.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isupper ( 'L', loc );
   bool result2 = isupper ( 'n', loc );
   bool result3 = isupper ( '3', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a uppercase character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a uppercase character." << endl;

   if ( result2 )
      cout << "The character 'n' in the locale is "
           << "a uppercase character." << endl;
   else
      cout << "The character 'n' in the locale is "
           << " not a uppercase character." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "a uppercase character." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not a uppercase character." << endl;
}

isxdigit

Tests whether an element in a locale is a character used to represent a hexadecimal number.

template <class CharType>
bool isxdigit(CharType Ch, const locale& Loc)

Parameters

Ch
The element to be tested.

Loc
The locale containing the element to be tested.

Return Value

true if the element tested is a character used to represent a hexadecimal number; false if it is not.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). is( ctype< CharType>:: xdigit, Ch).

Hexadecimal digits use base 16 to represent numbers, using the numbers 0 through 9 plus case-insensitive letters A through F to represent the decimal numbers 0 through 15.

Example

// locale_isxdigit.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   bool result1 = isxdigit ( '5', loc );
   bool result2 = isxdigit ( 'd', loc );
   bool result3 = isxdigit ( 'q', loc );

   if ( result1 )
      cout << "The character '5' in the locale is "
           << "a hexidecimal digit-character." << endl;
   else
      cout << "The character '5' in the locale is "
           << " not a hexidecimal digit-character." << endl;

   if ( result2 )
      cout << "The character 'd' in the locale is "
           << "a hexidecimal digit-character." << endl;
   else
      cout << "The character 'd' in the locale is "
           << " not a hexidecimal digit-character." << endl;

   if ( result3 )
      cout << "The character 'q' in the locale is "
           << "a hexidecimal digit-character." << endl;
   else
      cout << "The character 'q' in the locale is "
           << " not a hexidecimal digit-character." << endl;
}

tolower

Converts a character to lower case.

template <class CharType>
CharType tolower(CharType Ch, const locale& Loc)

Parameters

Ch
The character to be converted to lower case.

Loc
The locale containing the character to be converted.

Return Value

The character converted to lower case.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). tolower( Ch).

Example

// locale_tolower.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   char result1 = tolower ( 'H', loc );
   cout << "The lower case of 'H' in the locale is: "
        << result1 << "." << endl;
   char result2 = tolower ( 'h', loc );
   cout << "The lower case of 'h' in the locale is: "
        << result2 << "." << endl;
   char result3 = tolower ( '$', loc );
   cout << "The lower case of '$' in the locale is: "
        << result3 << "." << endl;
}

toupper

Converts a character to upper case.

template <class CharType>
CharType toupper(CharType Ch, const locale& Loc)

Parameters

Ch
The character to be converted to upper case.

Loc
The locale containing the character to be converted.

Return Value

The character converted to upper case.

Remarks

The template function returns use_facet< ctype< CharType> >( Loc). toupper( Ch).

Example

// locale_toupper.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
using namespace std;

int main( )
{
   locale loc ( "German_Germany" );
   char result1 = toupper ( 'h', loc );
   cout << "The upper case of 'h' in the locale is: "
        << result1 << "." << endl;
   char result2 = toupper ( 'H', loc );
   cout << "The upper case of 'H' in the locale is: "
        << result2 << "." << endl;
   char result3 = toupper ( '$', loc );
   cout << "The upper case of '$' in the locale is: "
        << result3 << "." << endl;
}

use_facet

Returns a reference to a facet of a specified type stored in a locale.

template <class Facet>
const Facet& use_facet(const locale& Loc);

Parameters

Loc
The const locale containing the type of facet being referenced.

Return Value

A reference to the facet of class Facet contained within the argument locale.

Remarks

The reference to the facet returned by the template function remains valid as long as any copy of the containing locale exists. If no such facet object of class Facet is listed in the argument locale, the function throws a bad_cast exception.

Example

// locale_use_facet.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
using namespace std;

int main( )
{
   locale loc1 ( "German_Germany" ), loc2 ( "English_Australia" );
   bool result1 = use_facet<ctype<char> > ( loc1 ).is(
   ctype_base::alpha, 'a'
);
   bool result2 = use_facet<ctype<char> > ( loc2 ).is( ctype_base::alpha, '!'
   );

   if ( result1 )
      cout << "The character 'a' in locale loc1 is alphabetic."
           << endl;
   else
      cout << "The character 'a' in locale loc1 is not alphabetic."
           << endl;

   if ( result2 )
      cout << "The character '!' in locale loc2 is alphabetic."
           << endl;
   else
      cout << "The character '!' in locale loc2 is not alphabetic."
           << endl;
}

The character 'a' in locale loc1 is alphabetic.
The character '!' in locale loc2 is not alphabetic.

See also

<locale>