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std::setbase(3)		      C++ Standard Libary	       std::setbase(3)

NAME
       std::setbase - std::setbase

Synopsis
	  Defined in header <iomanip>
	  /*unspecified*/ setbase( int base );

	  Sets	the numeric base of the	stream.	When used in an	expression out
       << setbase(base)
	  or in	>> setbase(base), changes the basefield	flag of	the stream out
       or in,
	  depending on the value of base:

	    * the value	16 sets	basefield to std::ios_base::hex.
	    * the value	8 sets std::ios_base::oct.
	    * the value	10 sets	std::ios_base::dec.

	  Values of base other than 8, 10, or  16  reset  basefield  to	 zero,
       which corresponds to
	  decimal output and prefix-dependent input.

Parameters
	  base - new value for basefield

Return value
	  An object of unspecified type	such that

	    *  if  out is an object of type std::basic_ostream<CharT, Traits>,
       the expression
	      out << setbase(base)
		 * has type std::basic_ostream<CharT, Traits>&
		 * has value out
		 * behaves as if it called f(out, base)
	    * if in is an object of  type  std::basic_istream<CharT,  Traits>,
       the expression in
	      >> setbase(base)
		 * has type std::basic_istream<CharT, Traits>&
		 * has value in
		 * behaves as if it called f(in, base)

	  where	the function f is defined as:

	void f(std::ios_base& str, int base)
	{
	    // set basefield
	    str.setf(base == 8 ? std::ios_base::oct :
		base ==	10 ? std::ios_base::dec	:
		base ==	16 ? std::ios_base::hex	:
		std::ios_base::fmtflags(0), std::ios_base::basefield);
	}

Example
       // Run this code

	#include <iomanip>
	#include <iostream>
	#include <sstream>

	int main()
	{
	    std::cout << "Parsing string \"10 0x10 010\"\n";

	    int	n1, n2,	n3;
	    std::istringstream s("10 0x10 010");

	    s >> std::setbase(16) >> n1	>> n2 >> n3;
	    std::cout << "hexadecimal parse: " << n1 <<	' ' << n2 << ' ' << n3
       << '\n';

	    s.clear();
	    s.seekg(0);

	    s >> std::setbase(0) >> n1 >> n2 >>	n3;
	    std::cout  << "prefix-dependent parse: " <<	n1 << '	' << n2	<< ' '
       << n3 <<	'\n';

	    std::cout << "hex output: "	<< std::setbase(16)
		      << std::showbase << n1 <<	' ' << n2 <<  '	 '  <<	n3  <<
       '\n';
	}

Output:
	Parsing	string "10 0x10	010"
	hexadecimal parse: 16 16 16
	prefix-dependent parse:	10 16 8
	hex output: 0xa	0x10 0x8

	  Defect reports

	  The following	behavior-changing defect reports were applied retroac-
       tively to
	  previously published C++ standards.

	    DR	   Applied  to		Behavior as published	       Correct
       behavior
	  LWG 183 C++98	     setbase could only	be used	 with  streams	usable
       with any
			     of	type std::ostream or std::istream    character
       stream

See also
	  dec	     changes the base used for integer I/O
	  hex	     (function)
	  oct
	  showbase   controls whether prefix is	used to	indicate numeric base
	  noshowbase (function)

http://cppreference.com		  2024.06.10		       std::setbase(3)

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