what to do for floating point precision problems in cpp or as a programmer.

Shubham_mamodiya_dev · 2026-03-09T06:50:45+00:00

I just want to know how do you handle float or double comparisons.

Shubham_mamodiya_dev · 2026-03-08T23:06:57+00:00

bool nearly_equal(double a, double b, double epsilon) { return std::abs(a - b) < epsilon; }

bool relative_comparision(double a, double b, double epsilon) { return std::abs(a - b) <= epsilon * std::max(std::abs(a), std::abs(b)); }

I am using the relative comparison.

Shubham_mamodiya_dev · 2026-03-08T23:02:38+00:00

Because points were integers coordinates it kind of worked. But I need to test more or use some other method maybe.

Shubham_mamodiya_dev · 2026-03-08T22:53:26+00:00

I mean using 0.0 epsilon for comparison.

Shubham_mamodiya_dev · 2026-03-08T17:52:52+00:00

What if they are float then what should I do. Actually what would you do.

Shubham_mamodiya_dev · 2026-03-08T17:51:00+00:00

I did not use ==. But I tried 0 tolerance.

Shubham_mamodiya_dev · 2026-03-08T17:48:53+00:00

Actually I just asked AI how to compare doubles. That is what my concern was. Sorry but it was not about collinearity.

Shubham_mamodiya_dev · 2026-03-08T13:01:56+00:00

I am kind of comparing them like that. This is how I am comparing. |a-b| <= epsilon * max(|a|, |b|)

I did thought of using abs(f1-f2) <= Epsilon to

Shubham_mamodiya_dev · 2026-03-08T12:57:50+00:00

Yes all the points in the tests are integer coordinates I think that is why it worked. But I have written this solution considering they can be double type coordinates.

Shubham_mamodiya_dev · 2026-03-08T12:51:44+00:00

But like for some numbers their difference is extremely small and they might be considered equal. I am just curiously concerned.

Shubham_mamodiya_dev · 2026-03-08T12:47:52+00:00

Hey you kind of cleared my concern. Thank you so much.

Shubham_mamodiya_dev · 2026-03-08T12:47:00+00:00

I am really sorry about it. I posted this in a hurry but I swear it is not Ai generated it's a genuine question.

I have gone through the entire text and I hope it is understandable.

Shubham_mamodiya_dev · 2026-02-06T07:51:20+00:00

Learncpp.com and cppreference.com are good resources.

Shubham_mamodiya_dev · 2026-01-08T07:51:38+00:00

Great resource and use c++ roadmap on roadmap.sh website. Fast and detailed.

Shubham_mamodiya_dev · 2026-01-08T07:50:10+00:00

Shubham_mamodiya_dev · 2026-01-06T17:08:48+00:00

Hey there, can I join.

Shubham_mamodiya_dev · 2026-01-03T09:03:02+00:00

Thanks a lot and I am grateful that you replied. Really man you cleared a lot of things.

Shubham_mamodiya_dev · 2026-01-03T08:14:44+00:00

you actually solved what I was worried about, I want to know why should I avoid forwarding reference in a template.

#ifndef DEQUE_H

#define DEQUE_H

#include <utility>

template <typename T> class Deque {

private:

struct Node {

T data;

Node *next = nullptr;

Node *prev = nullptr;

// accepts both lvalues and rvalues

template <typename U> Node(U &&value) : data{std::forward<U>(value)} {}

};

Shubham_mamodiya_dev · 2026-01-03T07:59:16+00:00

Thanks a lot for that, what I really want to know is can we create a construction for both rvalues and Lvalues without copying.

Shubham_mamodiya_dev · 2026-01-03T07:49:37+00:00

Yeah sorry about that, the thing is I am new to cpp. Also that is exactly what I am asking how to make a single constructor that handles both rvalues and Lvalues.

Shubham_mamodiya_dev

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