exp2

eve::exp2 = functor<exp2_t>

inlineconstexpr

Header file

#include <eve/module/math.hpp>

Callable Signatures

namespace eve
{
   // Regular overload
   constexpr auto exp2(value auto x)                          noexcept; // 1
 
   // Lanes masking
   constexpr auto exp2[conditional_expr auto c](value auto x) noexcept; // 2
   constexpr auto exp2[logical_value auto m](value auto x)    noexcept; // 2
}

Parameters

• x: value.
• c: Conditional expression masking the operation.
• m: Logical value masking the operation.

Return value

1. Returns the elementwise exponential of base 2 of the input. In particular, for floating inputs:
   • If the element is \(\pm0\), \(1\) is returned
   • If the element is \(-\infty\), \(+0\) is returned
   • If the element is \(\infty\), \(\infty\) is returned
   • If the element is a NaN, NaN is returned
2. The operation is performed conditionnaly.

Note

For integral negative entry, the result is zero.

External references

• C++ standard reference
• Wolfram MathWorld
• DLMF
• Wikipedia

Example

// revision 1
#include <eve/module/math.hpp>
#include <iostream>
 
int main()
{
  eve::wide wf = {0.0f, -0.0f, -1.0f, 1.0f, 2.0f,
                  eve::inf(eve::as<float>()), eve::minf(eve::as<float>()), eve::nan(eve::as<float>())};
  eve::wide<std::int32_t> wi([](auto i, auto c)->std::int32_t{ return i+c/2;});
  eve::wide<std::uint32_t> wu([](auto i, auto )->std::uint32_t{ return i;});
 
   std::cout << "<- wf = " << wf << "\n";
   std::cout << "<- wi = " << wi << "\n";
   std::cout << "<- wu = " << wu << "\n";
 
   std::cout << "-> exp2(wf)                = " << eve::exp2(wf) << "\n";
   std::cout << "-> exp2(wi)                = " << eve::exp2(wi) << "\n";
   std::cout << "-> exp2(wu)                = " << eve::exp2(wu) << "\n";
   std::cout << "-> exp2[ignore_last(2)](wf)= " << eve::exp2[eve::ignore_last(2)](wf) << "\n";
   std::cout << "-> exp2[ignore_last(2)](wi)= " << eve::exp2[eve::ignore_last(2)](wi) << "\n";
   std::cout << "-> exp2[ignore_last(2)](wu)= " << eve::exp2[eve::ignore_last(2)](wu) << "\n";
   std::cout << "-> exp2[wf != 2.0f](wf)    = " << eve::exp2[wf != 2.0f](wf) << "\n";
   std::cout << "-> exp2[wi != 4](wi)       = " << eve::exp2[wi != -2](wi) << "\n";
   std::cout << "-> exp2[wu != 2u](wu)      = " << eve::exp2[wu != 2u](wu) << "\n";
}