Dangerous while loop

Today a program I am writing stopped responding. After some debugging effort, I came across a 3rd party function that limited an input angle to the [-180, 180] degrees interval. It was using a while loop to increment or decrement the angle. Unfortunately, I was passing an uninitialized variable to it and its value was -9.2...e+61. Such a large value would take years for the function to limit. Below is the original function constrainAngleWhile(), together with much better alternatives:

	//Demonstrate different methods to limit an angle to the [-180, 180] degree interval.
	//To quickly test, paste code to https://www.onlinegdb.com/online_c++_compiler
	//Şamil Korkmaz, May 2022
	#include <iostream>
	#include <math.h>
	using namespace std;
	//https://stackoverflow.com/a/11498248/51358
	double constrainAngleMod(double x) {
	x = fmod(x + 180,360);
	if (x < 0) x += 360;
	return x - 180;
	}
	double constrainAngleWhile(double x) {
	double limitedX = x;
	//Note that the while loops below will take a long time if the input x is a large value.
	//For example, an unitialized variable can have a value like -9.2...e+61 which would take years!
	while (limitedX < -180) limitedX += 360;
	while (limitedX > 180) limitedX -= 360;
	return limitedX;
	}
	int main() {
	cout << "Calculating...\n";
	//Using remainder(): https://stackoverflow.com/a/11503585/51358
	cout << remainder(180, 360) << ", " << constrainAngleWhile(180) << endl;
	cout << remainder(181, 360) << ", " << constrainAngleWhile(181) << endl;
	cout << remainder(-181, 360) << ", "<< constrainAngleWhile(-181) << endl;
	cout << remainder(-359, 360) << ", "<< constrainAngleWhile(-359) << endl;
	cout << remainder(359, 360) << ", "<< constrainAngleWhile(359) << endl;
	cout << remainder(-360, 360) << ", "<< constrainAngleWhile(-360) << endl;
	cout << remainder(360, 360) << ", "<< constrainAngleWhile(360) << endl;
	double angle_deg = 1e12;
	cout << remainder(angle_deg, 360) << ", " << constrainAngleMod(angle_deg) << endl;
	cout << constrainAngleWhile(angle_deg) << endl;
	cout << "Finished.\n";
	return 0;
	}

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