"A small noncryptographic PRNG" in C++ as posted in burtleburtle.net.

BurtleRNG.cpp

#include <BurtleRNG.h>

BurtleRNG::BurtleRNG(const std::uint32_t &seed):
	a(0xf1ea5eed), b(seed), c(seed), d(seed)
{
	for (int i = 0; i != 20; i++) get();
}

std::uint32_t BurtleRNG::get() {
	#define rotate(x, k) (((x)<<(k)) | ((x)>>(32-(k))))
	const std::uint32_t e = a - rotate(b, 27);
	a = b ^ rotate(c, 17);
	b = c + d;
	c = d + e;
	d = e + a;
	return d;
	#undef rotate
}

std::uint32_t BurtleRNG::getInt(const std::uint32_t &bound) {
	std::uint32_t r = get() & (1u<<31)-1;
	const std::uint32_t m = bound-1;
	if ((bound & m) == 0) {
		r = bound*static_cast<std::uint64_t>(r) >> 31;
	} else {
		for (
			int u = r;
			u - (r = u%bound) + m < 0;
			u = get() & (1u<<31)-1
		);
	}
	return r;
}

double BurtleRNG::getDouble() {
	return (
		(static_cast<std::uint64_t>(get() & (1u<<26)-1) << 27)
		+ (get() & (1u<<27)-1)
	) * 0x1.0p-53;
}

float BurtleRNG::getFloat() {
	return (get() & (1u<<24)-1) / static_cast<float>(1u<<24);
}

BurtleRNG.h

// "A small noncryptographic PRNG" as originally posted in
// https://burtleburtle.net/bob/rand/smallprng.html

#pragma once

#include <cstdint>

class BurtleRNG {
	public:
		std::uint32_t a = 0, b = 0, c = 0, d = 0;
		BurtleRNG(const std::uint32_t &seed);
		std::uint32_t get();
		std::uint32_t getInt(const std::uint32_t &bound);
		double getDouble();
		float getFloat();
};