std::codecvt::length, std::codecvt::do_length
De cppreference.com
 [] |
This page has been machine-translated from the English version of the wiki using Google Translate.
The translation may contain errors and awkward wording. Hover over text to see the original version. You can help to fix errors and improve the translation. For instructions click here. |
![[]](https://upload.cppreference.com/mwiki/images/3/31/Imbox_notice.png){kind=link}
<metanoindex/>
<tbody> </tbody>| Dclar dans l'en-tte <locale>
|
||
public: int length( stateT& state, const externT* from, const externT* from_end, std::size_t max ) const |
(1) | |
protected: int do_length( stateT& state, const externT* from, const externT* from_end, std::size_t max ) const |
(2) | |
1)
fonction de membre du public, appelle le
do_length fonction membre de la classe la plus drive .Original:
public member function, calls the member function
do_length of the most derived class.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
2)
tente de convertir les caractres
externT du tableau de caractres dfini par [from, from_end), compte tenu de l'tat initial state la conversion, la plupart des max internT caractres, et renvoie le nombre de caractres externT que cette conversion serait consomment. Modifie state comme si en excutant do_in(state, from, from_end, from, to, to+max, to) pour certains tampon de sortie [to, to+max) imaginaire .Original:
attempts to convert the
externT characters from the character array defined by [from, from_end), given initial conversion state state, to at most max internT characters, and returns the number of externT characters that such conversion would consume. Modifies state as if by executing do_in(state, from, from_end, from, to, to+max, to) for some imaginary [to, to+max) output buffer.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Retourne la valeur
Le nombre de caractres
externT qui seraient consomms en cas de conversion par do_in() jusqu' ce que soit tous les caractres from_end-from ont t consommes ou max internT personnages taient un producteur ou une erreur de conversion produit .Original:
The number of
externT characters that would be consumed if converted by do_in() until either all from_end-from characters were consumed or max internT characters were producer, or a conversion error occurred.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
La spcialisation non-conversion
std::codecvt<char, char, std::mbstate_t> retours std::min(max, from_end-from)Original:
The non-converting specialization
std::codecvt<char, char, std::mbstate_t> returns std::min(max, from_end-from)The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Exemple
#include <locale>
#include <string>
#include <iostream>
int main()
{
// narrow multibyte encoding
std::string s = "z\u00df\u6c34\U0001d10b"; // or u8"z"
// or "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9d\x84\x8b";
std::mbstate_t mb = std::mbstate_t();
std::cout << "Only the first " <<
std::use_facet<std::codecvt<wchar_t, char, std::mbstate_t>>(
std::locale("en_US.utf8")
).length(mb, &s[0], &s[s.size()], 2)
<< " bytes out of " << s.size() << " would be consumed "
" to produce the first 2 characters\n";
}
Rsultat :
Only the first 3 bytes out of 10 would be consumed to produce the first 2 characters
Voir aussi
[ virtuel ]Original: virtual The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
convertit une chane de Externt internt, comme lors de la lecture du fichier Original: converts a string from externT to internT, such as when reading from file The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction membre virtuelle protge) |