significants

auto eve::significants = functor<significants_t>

inlineconstexpr

Header file

#include <eve/module/core.hpp>

Callable Signatures

namespace eve
{
   constexpr auto significants(auto floating_value x, auto unsigned_value n) noexcept;
}

Parameters

• x: floating argument.
• n : value argument.

Return value

Computes elementwise the rounding to n significants digits of x. With null n the result is a NaN.

Warning

Floating numbers are not stored in decimal form. So if you try significants with a not exactly representable number the result can be not exactly what you expect.

Example

// revision 1
#include <eve/module/math.hpp>
#include <iostream>
#include <iomanip>
 
int main()
{
  eve::wide<std::uint32_t, eve::fixed<8>> qi = {0u, 1u, 2u, 3u, 4u, 5u, 6u, 7u};
  float pf = 1.2345678901f;
 
   std::cout << std::setprecision(10);
   std::cout << "<- pf = " << pf << "\n";
   std::cout << "<- qi = " << qi << "\n";
   std::cout << std::setprecision(8);
   std::cout << "-> significants(pf, qi)= " << eve::significants(pf, qi) << "\n";
}