std::basic_string::npos
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<tbody> </tbody> static const size_type npos = -1; |
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Il s'agit d'une valeur spciale gale la valeur maximale reprsentable par le
size_type type. La signification exacte dpend du contexte, mais il est gnralement utilis comme indicateur de fin de chane par les fonctions qui attendent un indice chane ou l'indicateur d'erreur par les fonctions qui retournent un indice chane .Original:
This is a special value equal to the maximum value representable by the type
size_type. The exact meaning depends on context, but it is generally used either as end of string indicator by the functions that expect a string index or as the error indicator by the functions that return a string index.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 <iostream>
#include <bitset>
#include <string>
int main()
{
// string search functions return npos if nothing is found
std::string s = "test";
if(s.find('a') == std::string::npos)
std::cout << "no 'a' in 'test'\n";
// functions that take string subsets as arguments
// use npos as the "all the way to the end" indicator
std::string s2(s, 2, std::string::npos);
std::cout << s2 << '\n';
std::bitset<5> b("aaabb", std::string::npos, 'a', 'b');
std::cout << b << '\n';
}
Rsultat :
no 'a' in 'test'
st
00011