oop-praddy: setting precision in c++

Setting precision in c++

#include <iostream>

#include <limits>

#include <cmath>

#include <iomanip>

template < typename Float >

struct precision {

static unsigned int digits ( unsigned int base ) {

return( -

std::log( std::numeric_limits<Float>::epsilon() )

std::log( base ) );

}

};

template < typename Float >

unsigned int sig_digits ( Float const & ) {

return( precision<Float>::digits(10) ); }

int main ( void ) {

std::cout << precision<float>::digits( 10 )

<< " "

<< precision<double>::digits( 10 )

<< '\n';

float x = 2.3345467334234;

double y = 12.230912093719823691836;

std::cout << std::setprecision( sig_digits(x) ) << x << '\n';

std::cout << std::setprecision( sig_digits(y) ) << y << '\n'; }

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