std::basic_ios::operator!
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<tbody> </tbody> bool operator!() const; |
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true, wenn ein Fehler auf dem zugehörigen Stream aufgetreten. Insbesondere kehrt true wenn badbit oder failbit in rdstate() gesetzt .Original:
Returns
true if an error has occurred on the associated stream. Specifically, returns true if badbit or failbit is set in rdstate().The text has been machine-translated via Google Translate.
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Parameter
(None)
Original:
(none)
The text has been machine-translated via Google Translate.
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Rückgabewert
true wenn ein Fehler aufgetreten ist, ansonsten false .Original:
true if an error has occurred, false otherwise.The text has been machine-translated via Google Translate.
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Beispiel
#include <iostream>
#include <fstream>
#include <cstdlib>
int main()
{
std::ifstream file("test.txt");
if(!file) // operator! is used here
{
std::cout << "File opening failed\n";
return EXIT_FAILURE;
}
// typical C++ I/O loop uses the return value of the I/O function
// as the loop controlling condition, operator bool() is used here
for(int n; file >> n; ) {
std::cout << n << ' ';
}
std::cout << '\n';
if (file.bad())
std::cout << "I/O error while reading\n";
else if (file.eof())
std::cout << "End of file reached successfully\n";
else if (file.fail())
std::cout << "Non-integer data encountered\n";
}