atoi

Trait FromRadix10SignedChecked

Source 
pub trait FromRadix10SignedChecked: FromRadix10Signed {
    // Required method
    fn from_radix_10_signed_checked(_: &[u8]) -> (Option<Self>, usize);
}
Expand description

Types implementing this trait can be parsed from a positional numeral system with radix 10. Acts much like FromRadix10Signed, but performs additional checks for overflows.

Required Methods§

Source

fn from_radix_10_signed_checked(_: &[u8]) -> (Option<Self>, usize)

Parses an integer from a slice.

§Example
use atoi::FromRadix10SignedChecked;
// Parsing to digits from a slice
assert_eq!((Some(42),2), u32::from_radix_10_signed_checked(b"42"));
// Additional bytes after the number are ignored
assert_eq!((Some(42),2), u32::from_radix_10_signed_checked(b"42 is the answer to life, the universe and everything"));
// (0,0) is returned if the slice does not start with a digit
assert_eq!((Some(0),0), u32::from_radix_10_signed_checked(b"Sadly we do not know the question"));
// While signed integer types are supported...
assert_eq!((Some(42),2), i32::from_radix_10_signed_checked(b"42"));
// Signs are allowed
assert_eq!((Some(-42),3), i32::from_radix_10_signed_checked(b"-42"));
// -0 is ok, even for an unsigned type
assert_eq!((Some(0),2), u32::from_radix_10_signed_checked(b"-0"));
// -1 is an Underflow
assert_eq!((None,2), u32::from_radix_10_signed_checked(b"-1"));
// Negative values for unsigned types are handled as `None`.
assert_eq!((None,3), u32::from_radix_10_signed_checked(b"-42"));
// Leading zeros are allowed
assert_eq!((Some(42),4), u32::from_radix_10_signed_checked(b"0042"));
// Overflow is indicated by `None`
assert_eq!((None, 3), u8::from_radix_10_signed_checked(b"256"));
assert_eq!((None, 4), i8::from_radix_10_signed_checked(b"+128"));
assert_eq!((None, 4), i8::from_radix_10_signed_checked(b"-129"));
§Return

Returns a tuple with two numbers. The first is the integer parsed or zero if no digit has been found. None, if there were too many, or too high dighits and the parsing overflowed. The second is the index of the byte right after the parsed number. If the second element is zero the slice did not start with an ASCII digit.

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§