pub trait Num:
PartialEq
+ Zero
+ One
+ NumOps {
type FromStrRadixErr;
// Required method
fn from_str_radix(
str: &str,
radix: u32,
) -> Result<Self, Self::FromStrRadixErr>;
}
Expand description
The base trait for numeric types, covering 0
and 1
values,
comparisons, basic numeric operations, and string conversion.
Required Associated Types§
Required Methods§
Sourcefn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr>
fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr>
Convert from a string and radix (typically 2..=36
).
§Examples
use num_traits::Num;
let result = <i32 as Num>::from_str_radix("27", 10);
assert_eq!(result, Ok(27));
let result = <i32 as Num>::from_str_radix("foo", 10);
assert!(result.is_err());
§Supported radices
The exact range of supported radices is at the discretion of each type implementation. For
primitive integers, this is implemented by the inherent from_str_radix
methods in the
standard library, which panic if the radix is not in the range from 2 to 36. The
implementation in this crate for primitive floats is similar.
For third-party types, it is suggested that implementations should follow suit and at least
accept 2..=36
without panicking, but an Err
may be returned for any unsupported radix.
It’s possible that a type might not even support the common radix 10, nor any, if string
parsing doesn’t make sense for that type.
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.