MathUtilities.h

#ifndef XRPL_BASICS_MATHUTILITIES_H_INCLUDED
#define XRPL_BASICS_MATHUTILITIES_H_INCLUDED
 
#include <algorithm>
#include <cassert>
#include <cstddef>
 
namespace ripple {
 
constexpr std::size_t
calculatePercent(std::size_t count, std::size_t total)
{
    assert(total != 0);  // NOTE No XRPL_ASSERT here, because constexpr
    return ((std::min(count, total) * 100) + total - 1) / total;
}
 
// unit tests
static_assert(calculatePercent(1, 2) == 50);
static_assert(calculatePercent(0, 100) == 0);
static_assert(calculatePercent(100, 100) == 100);
static_assert(calculatePercent(200, 100) == 100);
static_assert(calculatePercent(1, 100) == 1);
static_assert(calculatePercent(1, 99) == 2);
static_assert(calculatePercent(6, 14) == 43);
static_assert(calculatePercent(29, 33) == 88);
static_assert(calculatePercent(1, 64) == 2);
static_assert(calculatePercent(0, 100'000'000) == 0);
static_assert(calculatePercent(1, 100'000'000) == 1);
static_assert(calculatePercent(50'000'000, 100'000'000) == 50);
static_assert(calculatePercent(50'000'001, 100'000'000) == 51);
static_assert(calculatePercent(99'999'999, 100'000'000) == 100);
 
}  // namespace ripple
 
#endif