pub trait AsPrimitive<T>: 'static + Copywhere
T: 'static + Copy,{
// Required method
fn as_(self) -> T;
}
Expand description
A generic interface for casting between machine scalars with the
as
operator, which admits narrowing and precision loss.
Implementers of this trait AsPrimitive
should behave like a primitive
numeric type (e.g. a newtype around another primitive), and the
intended conversion must never fail.
§Examples
let three: i32 = (3.14159265f32).as_();
assert_eq!(three, 3);
§Safety
Currently, some uses of the as
operator are not entirely safe.
In particular, it is undefined behavior if:
- A truncated floating point value cannot fit in the target integer type (#10184);
ⓘ
let x: u8 = (1.04E+17).as_(); // UB
- Or a floating point value does not fit in another floating point type (#15536).
ⓘ
let x: f32 = (1e300f64).as_(); // UB
Required Methods§
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.