rngxx/include/rngxx/crand.h

#pragma once


#include <rngxx.hpp>
#include "internal/mem.h"

#include "internal/common.h"

namespace rng
{
	struct crand final : public Random
	{
		// This range is inclusive
		constexpr static inline i64 RANGE_MIN = - (1L << 31);
		constexpr static inline i64 RANGE_MAX =   (1L << 31) - 1;

		crand();
		crand(u64 seed);

		inline ~crand() override{}
	
		RNG_OVERRIDE(inline i64, next_i64, ()) { return _sample_int(); }
		RNG_OVERRIDE(u64, next_u64,());

		RNG_OVERRIDE(i32, next_i32,());
		RNG_OVERRIDE(u32, next_u32,());

		RNG_OVERRIDE(void, next_bytes, (u8* p, usize n));
	protected:
		inline constexpr i64 _max_i64() const override { return RANGE_MAX; }
		inline constexpr u64 _max_u64() const override { return (u64)RANGE_MAX; }
		// the rest of the base `_max_*` functions are valid, as they will always be equal to or less than INT32_MAX (the upper bound of dr48.) 
		f64 _sample() override;
		void next_v64(u64* p, usize n) override;
		void next_v32(u32* p, usize n) override;
	private:
		struct _opaque;
		struct _deleter { static void delete_object(_opaque** st); };
		mem::aligned_ptr<_opaque, _deleter> _state;

		explicit crand(_opaque* raw);
		i64 _sample_int();
	};

}