Function pi 

pub fn pi<T>() -> T
where
    T: RealNumber,

The value of PI.

See also:

• four_over_pi
• half_pi
• one_over_pi
• one_over_two_pi
• quarter_pi
• root_half_pi
• root_pi
• root_two_pi
• three_over_two_pi
• two_over_pi
• two_over_root_pi
• two_pi