| 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 | |||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
| Integer formatting | |||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||
| Boolean formatting | |||||||||||||||||||||||||||||||
| Field width and fill control | |||||||||||||||||||||||||||||||
| Other formatting | |||||||||||||||||||||||||||||||
| Whitespace processing | |||||||||||||||||||||||||||||||
| Output flushing | |||||||||||||||||||||||||||||||
|
| ||||||||||||||||||||||||||||||
| Status flags manipulation | |||||||||||||||||||||||||||||||
| Time and money I/O | |||||||||||||||||||||||||||||||
| Quoted manipulator | |||||||||||||||||||||||||||||||
(C++14) | |||||||||||||||||||||||||||||||
Defined in header <ios> | ||
std::ios_base& showbase(std::ios_base& str); | (1) | |
std::ios_base& noshowbase(std::ios_base& str); | (2) | |
This is an I/O manipulator, it may be called with an expression such asout<< std::showbase for anyout of typestd::basic_ostream or with an expression such asin>> std::showbase for anyin of typestd::basic_istream.
Theshowbase flag affects the behavior of integer output (seestd::num_put::put), monetary input (seestd::money_get::get) and monetary output (seestd::money_put::put).
Contents |
| str | - | reference to I/O stream |
str (reference to the stream after manipulation).
As specifed instd::num_put::put, the showbase flag in integer output acts like the # format specifier instd::printf, which means the numeric base prefix isnot added when outputting the value zero.
#include <iomanip>#include <iostream>#include <locale>#include <sstream> int main(){// showbase affects the output of octals and hexadecimalsstd::cout<<std::hex<<"showbase: "<< std::showbase<<42<<'\n'<<"noshowbase: "<< std::noshowbase<<42<<'\n'; // and both input and output of monetary valuesstd::locale::global(std::locale("en_US.UTF8"));longdouble val=0;std::istringstream("3.14")>> std::showbase>>std::get_money(val);std::cout<<"With showbase, parsing 3.14 as money gives "<< val<<'\n';std::istringstream("3.14")>> std::noshowbase>>std::get_money(val);std::cout<<"Without showbase, parsing 3.14 as money gives "<< val<<'\n';}
Output:
showbase: 0x2anoshowbase: 2aWith showbase, parsing 3.14 as money gives 0Without showbase, parsing 3.14 as money gives 314
| clears the specified ios_base flags (function)[edit] | |
sets the specifiedios_base flags(function)[edit] |
