rngxx/include/rngxx/internal/seed.h

#pragma once

#include "common.h"

namespace rng
{
	template<typename T>
	struct seed_gen
	{
		virtual T generate_seed() = 0;

		inline virtual ~seed_gen(){}
	};

	namespace seed
	{
		struct splitmix64 : public virtual seed_gen<u64>
		{
			inline splitmix64(const splitmix64&) = default;
			explicit inline splitmix64(seed_gen<u64>& from) : m_state(from.generate_seed()){}
			splitmix64(u64 i);

			u64 generate_seed() override;
			f64 generate_f64();

			inline virtual ~splitmix64() override{}

			static u64 oneshot(u64& state);
			inline static u64 oneshot(const u64& state) { u64 s = state; return oneshot(s); }
			static f64 oneshotf(u64& state);
			inline static f64 oneshotf(const u64& state) { u64 s = state; return oneshotf(s); }
			static splitmix64 random();
		private:
			u64 m_state;
		};
	}
}