Trait num_traits::cast::NumCast [−][src]
pub trait NumCast: Sized + ToPrimitive { fn from<T: ToPrimitive>(n: T) -> Option<Self>; }
Expand description
An interface for casting between machine scalars.
Required methods
fn from<T: ToPrimitive>(n: T) -> Option<Self>
fn from<T: ToPrimitive>(n: T) -> Option<Self>
Creates a number from another value that can be converted into
a primitive via the ToPrimitive trait. If the source value cannot be
represented by the target type, then None is returned.
A value can be represented by the target type when it lies within
the range of scalars supported by the target type.
For example, a negative integer cannot be represented by an unsigned
integer type, and an i64 with a very high magnitude might not be
convertible to an i32.
On the other hand, conversions with possible precision loss or truncation
are admitted, like an f32 with a decimal part to an integer type, or
even a large f64 saturating to f32 infinity.