std::ios_base::fmtflags
From cppreference.com
typedef/*implementation defined*/ fmtflags; | ||
staticconstexpr fmtflags dec =/*implementation defined*/ staticconstexpr fmtflags oct =/*implementation defined*/ | ||
staticconstexpr fmtflags left =/*implementation defined*/ staticconstexpr fmtflags right =/*implementation defined*/ | ||
staticconstexpr fmtflags scientific =/*implementation defined*/ staticconstexpr fmtflags fixed =/*implementation defined*/ | ||
staticconstexpr fmtflags boolalpha =/*implementation defined*/ staticconstexpr fmtflags showbase =/*implementation defined*/ | ||
Specifies available formatting flags. It is a BitmaskType. The following constants are defined:
| Constant | Explanation |
| dec | use decimal base for integer I/O: see std::dec |
| oct | use octal base for integer I/O: see std::oct |
| hex | use hexadecimal base for integer I/O: see std::hex |
| basefield | dec | oct | hex. Useful for masking operations |
| left | left adjustment (adds fill characters to the right): see std::left |
| right | right adjustment (adds fill characters to the left): see std::right |
| internal | internal adjustment (adds fill characters to the internal designated point): see std::internal |
| adjustfield | left | right | internal. Useful for masking operations |
| scientific | generate floating point types using scientific notation, or hex notation if combined with fixed: see std::scientific |
| fixed | generate floating point types using fixed notation, or hex notation if combined with scientific: see std::fixed |
| floatfield | scientific | fixed. Useful for masking operations |
| boolalpha | insert and extract bool type in alphanumeric format: see std::boolalpha |
| showbase | generate a prefix indicating the numeric base for integer output, require the currency indicator in monetary I/O: see std::showbase |
| showpoint | generate a decimal-point character unconditionally for floating-point number output: see std::showpoint |
| showpos | generate a + character for non-negative numeric output: see std::showpos |
| skipws | skip leading whitespace before certain input operations: see std::skipws |
| unitbuf | flush the output after each output operation: see std::unitbuf |
| uppercase | replace certain lowercase letters with their uppercase equivalents in certain output operations: see std::uppercase |
[edit]Example
The following example shows several different ways to print the same result.
Run this code
#include <iostream> int main(){constint num =150; // using fmtflags as class member constants:std::cout.setf(std::ios_base::hex, std::ios_base::basefield);std::cout.setf(std::ios_base::showbase);std::cout<< num <<'\n'; // using fmtflags as inherited class member constants:std::cout.setf(std::ios::hex, std::ios::basefield);std::cout.setf(std::ios::showbase);std::cout<< num <<'\n'; // using fmtflags as object member constants:std::cout.setf(std::cout.hex, std::cout.basefield);std::cout.setf(std::cout.showbase);std::cout<< num <<'\n'; // using fmtflags as a type: std::ios_base::fmtflags ff; ff =std::cout.flags(); ff &= ~std::cout.basefield;// unset basefield bits ff |=std::cout.hex;// set hex ff |=std::cout.showbase;// set showbasestd::cout.flags(ff);std::cout<< num <<'\n'; // not using fmtflags, but using manipulators:std::cout<<std::hex<<std::showbase<< num <<'\n';}
Output:
0x96 0x96 0x96 0x96 0x96
[edit]See also
| manages format flags (public member function) | |
| sets specific format flag (public member function) | |
| clears specific format flag (public member function) | |
| changes the base used for integer I/O (function) | |
| changes the fill character (function template) | |
(C++11)(C++11) | changes formatting used for floating-point I/O (function) |
| controls whether prefix is used to indicate numeric base (function) | |
| switches between textual and numeric representation of booleans (function) | |
controls whether the + sign used with non-negative numbers (function) | |
| controls whether decimal point is always included in floating-point representation (function) | |
| controls whether output is flushed after each operation (function) | |
| controls whether leading whitespace is skipped on input (function) | |
| controls whether uppercase characters are used with some output formats (function) |
