prime_ceil

auto eve::prime_ceil = functor<prime_ceil_t>

inlineconstexpr

Header file

#include <eve/module/combinatorial.hpp>

Callable Signatures

namespace eve
{
   constexpr auto prime_floor(unsigned_value auto x) -> decltype(x) noexcept; //1
   template < integral_value T,  floating_scalar_value U>
   constexpr as_wide_as_t<U, T> prime_floor(T x, as<U>)             noexcept; //2
   template < integral_value T,  unsigned_scalar_value U>
   constexpr as_wide_as_t<U, T> prime_floor(T x, as<U>)             noexcept; //2
}

Parameters

• n: unsigned argument. If n is greater than 104'729, returns 0.

Return value

1. The smallest prime greater or equal to n.
2. Same, but the element type of the result is deduced from U.

External references

• Wikipedia: Prime number

Example

// revision 1
#include <eve/module/combinatorial.hpp>
#include <iostream>
 
eve::wide<std::uint32_t> wu([](auto i, auto )->std::uint32_t{ return i;});
eve::wide n{0u, 6u, 6542u, 15u, 104729u, 104730u, 10000u, 1000u};
 
int main(){
   std::cout << "<- wu = " << wu << "\n";
   std::cout << "<- n  = " << n << "\n";
 
   std::cout << "-> prime_ceil(wu)= " << eve::prime_ceil(wu) << "\n";
   std::cout << "-> prime_ceil(n) = " << eve::prime_ceil(n) << "\n";
   std::cout << "note 0 answer meaning 'out of implemented range'\n";
 
}