char_traits::to_char_type
Convertit un caractère int_type en un caractère correspondant char_type et retourne le résultat.
static char_type to_char_type(
const int_type& _Ch
);
Paramètres
- _Ch
Le caractère int_type à représenter comme un char_type.
Valeur de retour
Le caractère char_type correspondant au caractère int_type.
Une valeur de _Ch qui ne peut pas être représentée en tant tel génère un résultat non spécifié.
Notes
Les opérations de conversion to_int_type and to_char_type sont inversées les unes par rapport aux autres, afin que :
to_int_type ( to_char_type ( x ) ) == x
pour tout int_type X, et
to_char_type ( to_int_type ( x ) ) == x
pour tout char_type x
Exemple
// char_traits_to_char_type.cpp
// compile with: /EHsc
#include <string>
#include <iostream>
int main( )
{
using namespace std;
char_traits<char>::char_type ch1 = 'a';
char_traits<char>::char_type ch2 = 'b';
char_traits<char>::char_type ch3 = 'a';
// Converting from char_type to int_type
char_traits<char>::int_type int1, int2 , int3;
int1 =char_traits<char>:: to_int_type ( ch1 );
int2 =char_traits<char>:: to_int_type ( ch2 );
int3 =char_traits<char>:: to_int_type ( ch3 );
cout << "The char_types and corresponding int_types are:"
<< "\n ch1 = " << ch1 << " corresponding to int1 = "
<< int1 << "."
<< "\n ch2 = " << ch2 << " corresponding to int1 = "
<< int2 << "."
<< "\n ch3 = " << ch3 << " corresponding to int1 = "
<< int3 << "." << endl << endl;
// Converting from int_type back to char_type
char_traits<char>::char_type rec_ch1;
rec_ch1 = char_traits<char>:: to_char_type ( int1);
char_traits<char>::char_type rec_ch2;
rec_ch2 = char_traits<char>:: to_char_type ( int2);
cout << "The recovered char_types and corresponding int_types are:"
<< "\n recovered ch1 = " << rec_ch1 << " from int1 = "
<< int1 << "."
<< "\n recovered ch2 = " << rec_ch2 << " from int2 = "
<< int2 << "." << endl << endl;
// Testing that the conversions are inverse operations
bool b1 = char_traits<char>::eq ( rec_ch1 , ch1 );
if ( b1 )
cout << "The recovered char_type of ch1"
<< " is equal to the original ch1." << endl;
else
cout << "The recovered char_type of ch1"
<< " is not equal to the original ch1." << endl;
// An equivalent and alternatively test procedure
if ( rec_ch2 == ch2 )
cout << "The recovered char_type of ch2"
<< " is equal to the original ch2." << endl;
else
cout << "The recovered char_type of ch2"
<< " is not equal to the original ch2." << endl;
}
Configuration requise
En-tête : <chaîne>
Espace de noms : std