Hello , **I have 2 questions regarding std::f64::consts::PI**

##
Q1 : Is there a benefit (or motivation) behind specifying more than 14 digits below radix point for `PI`

?

According to the results I got from this experiment (in Rust Playground), **specifying 14 digits (in base 10) below radix point in code seems "enough" when storing a PI constant as f64**, since writing more digits doesn't affect the bit-level representation.

Meanwhile the definition of `std::f64::consts::PI`

specifies **35 digits below radix point in code.**

```
// (from rust/library/core/src/num/f64.rs)
pub const PI: f64 = 3.14159265358979323846264338327950288_f64;
```

##
Q2 : Confusing comment shown in docs page of `PI`

Docs page for `std::f64::consts::PI`

displays the definition of `PI`

constant as below:

```
pub const PI: f64 = 3.14159265358979323846264338327950288f64; // 3.1415926535897931f64
```

**What confuses me is the comment at the end of the line.**

It specifies only 16 digits below radix point and the 16th digit ("**1**") differs from the 16th digit of the value stored to `PI`

in code ("**0**").

Rounding the `PI`

constant to the 16th digit doesn't result in the value specified in the comment.

When I looked at the source (by clicking the `source`

button in the docs page), I couldn't find such comment in the same file.

**How is that comment generated? What information does it intend to give us?**