I/O manipulators | ||||
Print functions(C++23) | ||||
C-style I/O | ||||
Buffers | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++20) | ||||
Streams | ||||
Abstractions | ||||
File I/O | ||||
String I/O | ||||
Array I/O | ||||
(C++23) | ||||
(C++23) | ||||
(C++23) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
(C++98/26*) | ||||
Synchronized Output | ||||
(C++20) | ||||
Types | ||||
Error category interface | ||||
(C++11) | ||||
(C++11) |
Floating-point formatting | |||||||||||||||||||||||||||||||
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Integer formatting | |||||||||||||||||||||||||||||||
Boolean formatting | |||||||||||||||||||||||||||||||
boolalphanoboolalpha | |||||||||||||||||||||||||||||||
Field width and fill control | |||||||||||||||||||||||||||||||
Other formatting | |||||||||||||||||||||||||||||||
Whitespace processing | |||||||||||||||||||||||||||||||
Output flushing | |||||||||||||||||||||||||||||||
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Status flags manipulation | |||||||||||||||||||||||||||||||
Time and money I/O | |||||||||||||||||||||||||||||||
Quoted manipulator | |||||||||||||||||||||||||||||||
(C++14) |
Defined in header <ios> | ||
std::ios_base& boolalpha(std::ios_base& str); | (1) | |
std::ios_base& noboolalpha(std::ios_base& str); | (2) | |
boolalpha
flag in the streamstr as if by callingstr.unsetf(std::ios_base::boolalpha).std::boolalpha
is an I/O manipulator, so it may be called with an expression such asout<< std::boolalpha for anyout
of typestd::basic_ostream or with an expression such asin>> std::boolalpha for anyin
of typestd::basic_istream.
Contents |
str | - | reference to I/O stream |
str (reference to the stream after manipulation).
#include <iostream>#include <sstream> int main(){// boolalpha outputstd::cout<<"default true: "<<true<<'\n'<<"default false: "<<false<<'\n'<< std::boolalpha<<"boolalpha true: "<<true<<'\n'<<"boolalpha false: "<<false<<'\n'<< std::noboolalpha<<"noboolalpha true: "<<true<<'\n'<<"noboolalpha false: "<<false<<'\n'; // boolalpha parsebool b1, b2;std::istringstream is("true false"); is>> std::boolalpha>> b1>> b2; std::cout<<'"'<< is.str()<<"\" parsed as: "<< std::boolalpha<< b1<<' '<< b2<<'\n';}
Output:
default true: 1default false: 0boolalpha true: trueboolalpha false: falsenoboolalpha true: 1noboolalpha false: 0"true false" parsed as: true false
clears the specified ios_base flags (function)[edit] | |
sets the specifiedios_base flags(function)[edit] | |
[virtual] | provides the string to use as the name of the booleantrue andfalse (virtual protected member function of std::numpunct<CharT> )[edit] |