Trait WrappingAs

pub trait WrappingAs {
    // Required method
    fn wrapping_as<Dst>(self) -> Dst
       where Self: WrappingCast<Dst>;
}

Wrapping cast.

This is a convenience trait to enable writing src.wrapping_as::<Dst>(). This would not work with the WrappingCast::wrapping_cast method because the WrappingCast trait is generic while its WrappingCast::wrapping_cast method is not generic.

This trait’s method is suitable for chaining.

If there is an implementation of WrappingCast<Dst> for &Src but not for Src, and the variable src is of type Src, then src.wrapping_as::<Dst>() would not work and (&src).wrapping_as::<Dst>() is not easy to use with chaining, but src.borrow().wrapping_as::<Dst>() works.

Panics

This trait’s method panics if the value does not fit and cannot be wrapped, for example when trying to cast floating-point ∞ into an integer type.

Examples

use az::WrappingAs;
assert_eq!((-1).wrapping_as::<u32>(), u32::max_value());
assert_eq!((17.0 + 256.0).wrapping_as::<u8>(), 17);

The following example shows how this trait can be used when WrappingCast is implemented for a reference type.

use az::{WrappingAs, WrappingCast};
use core::borrow::Borrow;
struct I(i32);
impl WrappingCast<u32> for &'_ I {
    fn wrapping_cast(self) -> u32 { self.0.wrapping_cast() }
}

let r = &I(-5);
assert_eq!(r.wrapping_as::<u32>(), 5u32.wrapping_neg());
let owned = I(12);
assert_eq!(owned.borrow().wrapping_as::<u32>(), 12);

Required Methods

fn wrapping_as<Dst>(self) -> Dst

where Self: WrappingCast<Dst>,

Casts the value.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> WrappingAs for T