blob: 7888dbaa77dd5749679880f617b50240ef803de5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
#include "random.hpp"
#include <random>
#include <limits>
namespace floormat {
static thread_local auto g = std::independent_bits_engine<decltype(std::ranlux48{}), 32, std::uint32_t>{std::ranlux48{}};
random_engine::~random_engine() = default;
struct random_engine_impl final : random_engine {
std::size_t operator()() override;
float operator()(float min, float max) override;
};
std::size_t random_engine_impl::operator()()
{
if constexpr(sizeof(std::size_t) > sizeof(std::uint32_t))
{
constexpr auto N = (sizeof(std::size_t) + sizeof(std::uint32_t)-1) / sizeof(std::uint32_t);
static_assert(N >= 1);
union {
std::size_t x;
std::uint32_t a[N];
} ret;
for (auto i = 0_uz; i < N; i++)
ret.a[i] = g();
return ret.x;
}
else
return (std::size_t)g();
}
float random_engine_impl::operator()(float min, float max)
{
std::uniform_real_distribution<float> dist{min, max};
return dist(g);
}
static random_engine& make_random_impl() {
static random_engine_impl ret;
return ret;
}
random_engine& random = make_random_impl();
} // namespace floormat
|
