std::fixed, std::scientific, std::hexfloat, std::defaultfloat
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<metanoindex/>
<tbody> </tbody>| Déclaré dans l'en-tête <ios>
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std::ios_base& fixed( std::ios_base& str ); |
(1) | |
std::ios_base& scientific( std::ios_base& str ); |
(2) | |
std::ios_base& hexfloat( std::ios_base& str ); |
(3) | (depuis C++11) |
std::ios_base& defaultfloat( std::ios_base& str ); |
(4) | (depuis C++11) |
Modifie le formatage par défaut en virgule flottante I / O
Original:
Modifies the default formatting for floating-point I/O
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1)
définit le
floatfield de la str flux de fixed comme si en appelant str.setf(std::ios_base::fixed, std::ios_base::floatfield)Original:
sets the
floatfield of the stream str to fixed as if by calling str.setf(std::ios_base::fixed, std::ios_base::floatfield)The text has been machine-translated via Google Translate.
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2)
définit le
floatfield de la str flux de scientific comme si en appelant str.setf(std::ios_base::scientific, std::ios_base::floatfield)Original:
sets the
floatfield of the stream str to scientific as if by calling str.setf(std::ios_base::scientific, std::ios_base::floatfield)The text has been machine-translated via Google Translate.
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3)
définit le
basefield du flux str à fixed et scientific simultanément, comme si en appelant str.setf(std::ios_base::fixed | std::ios_base::scientific, std::ios_base::floatfield). Cela permet hexadécimal à virgule flottante en forme .Original:
sets the
basefield of the stream str to fixed and scientific simultaneously as if by calling str.setf(std::ios_base::fixed | std::ios_base::scientific, std::ios_base::floatfield). This enables hexadecimal floating-point formatting.The text has been machine-translated via Google Translate.
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4)
définit le
basefield de la str flux à zéro, comme si en appelant str.unsetf(std::ios_base::floatfield). Ceci permet à la virgule flottante par défaut de mise en forme, qui est différente de fixe et scientifique .Original:
sets the
basefield of the stream str to zero, as if by calling str.unsetf(std::ios_base::floatfield). This enables the default floating-point formatting, which is different from fixed and scientific.The text has been machine-translated via Google Translate.
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Il s'agit d'un manipulateur d'E / S, il peut être appelé avec une expression telle que pour tout
out << std::fixed out de std::basic_ostream type ou d'une expression telle que pour tout in >> std::scientific in de std::basic_istream type .Original:
This is an I/O manipulator, it may be called with an expression such as
out << std::fixed for any out of type std::basic_ostream or with an expression such as in >> std::scientific for any in of type std::basic_istream.The text has been machine-translated via Google Translate.
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Paramètres
| str | - | référence aux flux d'entrée / sortie
Original: reference to I/O stream The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Retourne la valeur
str (référence au flux après la manipulation)Original:
str (reference to the stream after manipulation)The text has been machine-translated via Google Translate.
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Exemple
#include <iostream>
#include <sstream>
int main()
{
std::cout << "The number 0.01 in fixed: " << std::fixed << 0.01 << '\n'
<< "The number 0.01 in scientific: " << std::scientific << 0.01 << '\n'
<< "The number 0.01 in hexfloat: " << std::hexfloat << 0.01 << '\n'
<< "The number 0.01 in default: " << std::defaultfloat << 0.01 << '\n';
double f;
std::istringstream("0x1P-1022") >> std::hexfloat >> f;
std::cout << "Parsing 0x1P-1022 as hex gives " << f << '\n';
}
Résultat :
The number 0.01 in fixed: 0.010000
The number 0.01 in scientific: 1.000000e-02
The number 0.01 in hexfloat: 0x1.47ae147ae147bp-7
The number 0.01 in default: 0.01
Parsing 0x1P-1022 as hex gives 2.22507e-308
Voir aussi
changements à virgule flottante de précision Original: changes floating-point precision The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction) |