Trait sp_std::convert::TryFrom

pub trait TryFrom<T> {
    type Error;
    fn try_from(value: T) -> Result<Self, Self::Error>;
}

Simple and safe type conversions that may fail in a controlled way under some circumstances. It is the reciprocal of TryInto.

This is useful when you are doing a type conversion that may trivially succeed but may also need special handling. For example, there is no way to convert an i64 into an i32 using the From trait, because an i64 may contain a value that an i32 cannot represent and so the conversion would lose data. This might be handled by truncating the i64 to an i32 (essentially giving the i64’s value modulo i32::MAX) or by simply returning i32::MAX, or by some other method. The From trait is intended for perfect conversions, so the TryFrom trait informs the programmer when a type conversion could go bad and lets them decide how to handle it.

Generic Implementations

• TryFrom<T> for U implies TryInto<U> for T
• try_from is reflexive, which means that TryFrom<T> for T is implemented and cannot fail – the associated Error type for calling T::try_from() on a value of type T is Infallible. When the ! type is stabilized Infallible and ! will be equivalent.

TryFrom<T> can be implemented as follows:

use std::convert::TryFrom;

struct GreaterThanZero(i32);

impl TryFrom<i32> for GreaterThanZero {
    type Error = &'static str;

    fn try_from(value: i32) -> Result<Self, Self::Error> {
        if value <= 0 {
            Err("GreaterThanZero only accepts value superior than zero!")
        } else {
            Ok(GreaterThanZero(value))
        }
    }
}

Examples

As described, i32 implements TryFrom<i64>:

use std::convert::TryFrom;

let big_number = 1_000_000_000_000i64;
// Silently truncates `big_number`, requires detecting
// and handling the truncation after the fact.
let smaller_number = big_number as i32;
assert_eq!(smaller_number, -727379968);

// Returns an error because `big_number` is too big to
// fit in an `i32`.
let try_smaller_number = i32::try_from(big_number);
assert!(try_smaller_number.is_err());

// Returns `Ok(3)`.
let try_successful_smaller_number = i32::try_from(3);
assert!(try_successful_smaller_number.is_ok());

Associated Types

type Error

The type returned in the event of a conversion error.

Required methods

fn try_from(value: T) -> Result<Self, Self::Error>

Performs the conversion.

Implementations on Foreign Types

impl TryFrom<u32> for i8

pub fn try_from(u: u32) -> Result<i8, <i8 as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for usize

pub fn try_from(u: i8) -> Result<usize, <usize as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for u128

pub fn try_from(u: i16) -> Result<u128, <u128 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for i16

pub fn try_from(u: isize) -> Result<i16, <i16 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for i8

pub fn try_from(u: isize) -> Result<i8, <i8 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u16> for u8

pub fn try_from(u: u16) -> Result<u8, <u8 as TryFrom<u16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for i32

pub fn try_from(u: i128) -> Result<i32, <i32 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for u16

pub fn try_from(u: i32) -> Result<u16, <u16 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for u32

pub fn try_from(u: usize) -> Result<u32, <u32 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for u64

pub fn try_from(u: isize) -> Result<u64, <u64 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u16> for i16

pub fn try_from(u: u16) -> Result<i16, <i16 as TryFrom<u16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for usize

pub fn try_from(value: u32) -> Result<usize, <usize as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for u8

pub fn try_from(u: i32) -> Result<u8, <u8 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for i16

pub fn try_from(u: u128) -> Result<i16, <i16 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for i64

pub fn try_from(u: i128) -> Result<i64, <i64 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for i8

pub fn try_from(u: u128) -> Result<i8, <i8 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for usize

pub fn try_from(u: i16) -> Result<usize, <usize as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for i128

pub fn try_from(value: isize) -> Result<i128, <i128 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for u8

pub fn try_from(u: u32) -> Result<u8, <u8 as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for u64

pub fn try_from(u: i16) -> Result<u64, <u64 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for i8

pub fn try_from(u: i128) -> Result<i8, <i8 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for u16

pub fn try_from(u: i64) -> Result<u16, <u16 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for u64

pub fn try_from(value: usize) -> Result<u64, <u64 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl<'_, T, const N: usize> TryFrom<&'_ [T]> for [T; N] where
    T: Copy, 

type Error = TryFromSliceError

pub fn try_from(slice: &[T]) -> Result<[T; N], TryFromSliceError>

impl TryFrom<i128> for isize

pub fn try_from(u: i128) -> Result<isize, <isize as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for i8

pub fn try_from(u: usize) -> Result<i8, <i8 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for u8

pub fn try_from(u: i64) -> Result<u8, <u8 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for u128

pub fn try_from(u: i64) -> Result<u128, <u128 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for u8

pub fn try_from(u: i8) -> Result<u8, <u8 as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for u8

pub fn try_from(u: usize) -> Result<u8, <u8 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for u64

pub fn try_from(u: i8) -> Result<u64, <u64 as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for i128

pub fn try_from(value: usize) -> Result<i128, <i128 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for u32

pub fn try_from(u: i16) -> Result<u32, <u32 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for isize

pub fn try_from(value: u32) -> Result<isize, <isize as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for i128

pub fn try_from(u: u128) -> Result<i128, <i128 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for usize

pub fn try_from(value: u64) -> Result<usize, <usize as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for u128

pub fn try_from(u: i128) -> Result<u128, <u128 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u16> for isize

pub fn try_from(value: u16) -> Result<isize, <isize as TryFrom<u16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for i16

pub fn try_from(u: i128) -> Result<i16, <i16 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for i8

pub fn try_from(u: u64) -> Result<i8, <i8 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for u128

pub fn try_from(value: usize) -> Result<u128, <u128 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for char

type Error = CharTryFromError

pub fn try_from(i: u32) -> Result<char, <char as TryFrom<u32>>::Error>

impl TryFrom<u8> for i8

pub fn try_from(u: u8) -> Result<i8, <i8 as TryFrom<u8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for u32

pub fn try_from(u: u64) -> Result<u32, <u32 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for u16

pub fn try_from(u: u128) -> Result<u16, <u16 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for usize

pub fn try_from(u: i32) -> Result<usize, <usize as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for i8

pub fn try_from(u: i64) -> Result<i8, <i8 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for u32

pub fn try_from(u: i128) -> Result<u32, <u32 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for i8

pub fn try_from(u: i16) -> Result<i8, <i8 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for i16

pub fn try_from(u: i32) -> Result<i16, <i16 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for u32

pub fn try_from(u: u128) -> Result<u32, <u32 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for u16

pub fn try_from(u: usize) -> Result<u16, <u16 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for u64

pub fn try_from(u: u128) -> Result<u64, <u64 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for u8

pub fn try_from(u: i128) -> Result<u8, <u8 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for u16

pub fn try_from(u: u64) -> Result<u16, <u16 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for u32

pub fn try_from(u: i8) -> Result<u32, <u32 as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for u64

pub fn try_from(u: i32) -> Result<u64, <u64 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for u128

pub fn try_from(u: isize) -> Result<u128, <u128 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for i64

pub fn try_from(u: usize) -> Result<i64, <i64 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for i32

pub fn try_from(u: i64) -> Result<i32, <i32 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for u64

pub fn try_from(u: i128) -> Result<u64, <u64 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl<'a, T, const N: usize> TryFrom<&'a mut [T]> for &'a mut [T; N]

type Error = TryFromSliceError

pub fn try_from(slice: &mut [T]) -> Result<&mut [T; N], TryFromSliceError>

impl TryFrom<i32> for u32

pub fn try_from(u: i32) -> Result<u32, <u32 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for i16

pub fn try_from(u: usize) -> Result<i16, <i16 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for u16

pub fn try_from(u: u32) -> Result<u16, <u16 as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N]

type Error = TryFromSliceError

pub fn try_from(slice: &[T]) -> Result<&[T; N], TryFromSliceError>

impl TryFrom<u128> for i64

pub fn try_from(u: u128) -> Result<i64, <i64 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for i16

pub fn try_from(u: u32) -> Result<i16, <i16 as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for i32

pub fn try_from(u: u64) -> Result<i32, <i32 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for u16

pub fn try_from(u: i16) -> Result<u16, <u16 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for u64

pub fn try_from(u: i64) -> Result<u64, <u64 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for i16

pub fn try_from(u: u64) -> Result<i16, <i16 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for u128

pub fn try_from(u: i32) -> Result<u128, <u128 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for u16

pub fn try_from(u: i8) -> Result<u16, <u16 as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for u16

pub fn try_from(u: i128) -> Result<u16, <u16 as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for u32

pub fn try_from(u: i64) -> Result<u32, <u32 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for isize

pub fn try_from(u: u128) -> Result<isize, <isize as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for usize

pub fn try_from(u: isize) -> Result<usize, <usize as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for isize

pub fn try_from(value: i32) -> Result<isize, <isize as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for i32

pub fn try_from(u: u128) -> Result<i32, <i32 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for i64

pub fn try_from(value: isize) -> Result<i64, <i64 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for isize

pub fn try_from(u: u64) -> Result<isize, <isize as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for u16

pub fn try_from(u: isize) -> Result<u16, <u16 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for usize

pub fn try_from(u: i64) -> Result<usize, <usize as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i16> for u8

pub fn try_from(u: i16) -> Result<u8, <u8 as TryFrom<i16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i32> for i8

pub fn try_from(u: i32) -> Result<i8, <i8 as TryFrom<i32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i8> for u128

pub fn try_from(u: i8) -> Result<u128, <u128 as TryFrom<i8>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for i32

pub fn try_from(u: isize) -> Result<i32, <i32 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for isize

pub fn try_from(value: i64) -> Result<isize, <isize as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for isize

pub fn try_from(u: usize) -> Result<isize, <isize as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for usize

pub fn try_from(u: u128) -> Result<usize, <usize as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i128> for usize

pub fn try_from(u: i128) -> Result<usize, <usize as TryFrom<i128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for u8

pub fn try_from(u: u64) -> Result<u8, <u8 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u32> for i32

pub fn try_from(u: u32) -> Result<i32, <i32 as TryFrom<u32>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u128> for u8

pub fn try_from(u: u128) -> Result<u8, <u8 as TryFrom<u128>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for u8

pub fn try_from(u: isize) -> Result<u8, <u8 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u16> for i8

pub fn try_from(u: u16) -> Result<i8, <i8 as TryFrom<u16>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<i64> for i16

pub fn try_from(u: i64) -> Result<i16, <i16 as TryFrom<i64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<usize> for i32

pub fn try_from(u: usize) -> Result<i32, <i32 as TryFrom<usize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<u64> for i64

pub fn try_from(u: u64) -> Result<i64, <i64 as TryFrom<u64>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl TryFrom<isize> for u32

pub fn try_from(u: isize) -> Result<u32, <u32 as TryFrom<isize>>::Error>

Try to create the target number type from a source number type. This returns an error if the source value is outside of the range of the target type.

type Error = TryFromIntError

impl<T, A, const N: usize> TryFrom<Vec<T, A>> for [T; N] where
    A: Allocator, 

pub fn try_from(vec: Vec<T, A>) -> Result<[T; N], Vec<T, A>>

Gets the entire contents of the Vec<T> as an array, if its size exactly matches that of the requested array.

Examples

use std::convert::TryInto;
assert_eq!(vec![1, 2, 3].try_into(), Ok([1, 2, 3]));
assert_eq!(<Vec<i32>>::new().try_into(), Ok([]));

If the length doesn’t match, the input comes back in Err:

use std::convert::TryInto;
let r: Result<[i32; 4], _> = (0..10).collect::<Vec<_>>().try_into();
assert_eq!(r, Err(vec![0, 1, 2, 3, 4, 5, 6, 7, 8, 9]));

If you’re fine with just getting a prefix of the Vec<T>, you can call .truncate(N) first.

use std::convert::TryInto;
let mut v = String::from("hello world").into_bytes();
v.sort();
v.truncate(2);
let [a, b]: [_; 2] = v.try_into().unwrap();
assert_eq!(a, b' ');
assert_eq!(b, b'd');

type Error = Vec<T, A>

Implementors

impl TryFrom<i8> for NonZeroI8

impl TryFrom<i16> for NonZeroI16

impl TryFrom<i32> for NonZeroI32

impl TryFrom<i64> for NonZeroI64

impl TryFrom<i128> for NonZeroI128

impl TryFrom<isize> for NonZeroIsize

impl TryFrom<u8> for NonZeroU8

impl TryFrom<u16> for NonZeroU16

impl TryFrom<u32> for NonZeroU32

impl TryFrom<u64> for NonZeroU64

impl TryFrom<u128> for NonZeroU128

impl TryFrom<usize> for NonZeroUsize

impl TryFrom<NonZeroI8> for NonZeroU8

impl TryFrom<NonZeroI8> for NonZeroU16

impl TryFrom<NonZeroI8> for NonZeroU32

impl TryFrom<NonZeroI8> for NonZeroU64

impl TryFrom<NonZeroI8> for NonZeroU128

impl TryFrom<NonZeroI8> for NonZeroUsize

impl TryFrom<NonZeroI16> for NonZeroI8

impl TryFrom<NonZeroI16> for NonZeroU8

impl TryFrom<NonZeroI16> for NonZeroU16

impl TryFrom<NonZeroI16> for NonZeroU32

impl TryFrom<NonZeroI16> for NonZeroU64

impl TryFrom<NonZeroI16> for NonZeroU128

impl TryFrom<NonZeroI16> for NonZeroUsize

impl TryFrom<NonZeroI32> for NonZeroI8

impl TryFrom<NonZeroI32> for NonZeroI16

impl TryFrom<NonZeroI32> for NonZeroIsize

impl TryFrom<NonZeroI32> for NonZeroU8

impl TryFrom<NonZeroI32> for NonZeroU16

impl TryFrom<NonZeroI32> for NonZeroU32

impl TryFrom<NonZeroI32> for NonZeroU64

impl TryFrom<NonZeroI32> for NonZeroU128

impl TryFrom<NonZeroI32> for NonZeroUsize

impl TryFrom<NonZeroI64> for NonZeroI8

impl TryFrom<NonZeroI64> for NonZeroI16

impl TryFrom<NonZeroI64> for NonZeroI32

impl TryFrom<NonZeroI64> for NonZeroIsize

impl TryFrom<NonZeroI64> for NonZeroU8

impl TryFrom<NonZeroI64> for NonZeroU16

impl TryFrom<NonZeroI64> for NonZeroU32

impl TryFrom<NonZeroI64> for NonZeroU64

impl TryFrom<NonZeroI64> for NonZeroU128

impl TryFrom<NonZeroI64> for NonZeroUsize

impl TryFrom<NonZeroI128> for NonZeroI8

impl TryFrom<NonZeroI128> for NonZeroI16

impl TryFrom<NonZeroI128> for NonZeroI32

impl TryFrom<NonZeroI128> for NonZeroI64

impl TryFrom<NonZeroI128> for NonZeroIsize

impl TryFrom<NonZeroI128> for NonZeroU8

impl TryFrom<NonZeroI128> for NonZeroU16

impl TryFrom<NonZeroI128> for NonZeroU32

impl TryFrom<NonZeroI128> for NonZeroU64

impl TryFrom<NonZeroI128> for NonZeroU128

impl TryFrom<NonZeroI128> for NonZeroUsize

impl TryFrom<NonZeroIsize> for NonZeroI8

impl TryFrom<NonZeroIsize> for NonZeroI16

impl TryFrom<NonZeroIsize> for NonZeroI32

impl TryFrom<NonZeroIsize> for NonZeroI64

impl TryFrom<NonZeroIsize> for NonZeroI128

impl TryFrom<NonZeroIsize> for NonZeroU8

impl TryFrom<NonZeroIsize> for NonZeroU16

impl TryFrom<NonZeroIsize> for NonZeroU32

impl TryFrom<NonZeroIsize> for NonZeroU64

impl TryFrom<NonZeroIsize> for NonZeroU128

impl TryFrom<NonZeroIsize> for NonZeroUsize

impl TryFrom<NonZeroU8> for NonZeroI8

impl TryFrom<NonZeroU16> for NonZeroI8

impl TryFrom<NonZeroU16> for NonZeroI16

impl TryFrom<NonZeroU16> for NonZeroIsize

impl TryFrom<NonZeroU16> for NonZeroU8

impl TryFrom<NonZeroU32> for NonZeroI8

impl TryFrom<NonZeroU32> for NonZeroI16

impl TryFrom<NonZeroU32> for NonZeroI32

impl TryFrom<NonZeroU32> for NonZeroIsize

impl TryFrom<NonZeroU32> for NonZeroU8

impl TryFrom<NonZeroU32> for NonZeroU16

impl TryFrom<NonZeroU32> for NonZeroUsize

impl TryFrom<NonZeroU64> for NonZeroI8

impl TryFrom<NonZeroU64> for NonZeroI16

impl TryFrom<NonZeroU64> for NonZeroI32

impl TryFrom<NonZeroU64> for NonZeroI64

impl TryFrom<NonZeroU64> for NonZeroIsize

impl TryFrom<NonZeroU64> for NonZeroU8

impl TryFrom<NonZeroU64> for NonZeroU16

impl TryFrom<NonZeroU64> for NonZeroU32

impl TryFrom<NonZeroU64> for NonZeroUsize

impl TryFrom<NonZeroU128> for NonZeroI8

impl TryFrom<NonZeroU128> for NonZeroI16

impl TryFrom<NonZeroU128> for NonZeroI32

impl TryFrom<NonZeroU128> for NonZeroI64

impl TryFrom<NonZeroU128> for NonZeroI128

impl TryFrom<NonZeroU128> for NonZeroIsize

impl TryFrom<NonZeroU128> for NonZeroU8

impl TryFrom<NonZeroU128> for NonZeroU16

impl TryFrom<NonZeroU128> for NonZeroU32

impl TryFrom<NonZeroU128> for NonZeroU64

impl TryFrom<NonZeroU128> for NonZeroUsize

impl TryFrom<NonZeroUsize> for NonZeroI8

impl TryFrom<NonZeroUsize> for NonZeroI16

impl TryFrom<NonZeroUsize> for NonZeroI32

impl TryFrom<NonZeroUsize> for NonZeroI64

impl TryFrom<NonZeroUsize> for NonZeroI128

impl TryFrom<NonZeroUsize> for NonZeroIsize

impl TryFrom<NonZeroUsize> for NonZeroU8

impl TryFrom<NonZeroUsize> for NonZeroU16

impl TryFrom<NonZeroUsize> for NonZeroU32

impl TryFrom<NonZeroUsize> for NonZeroU64

impl TryFrom<NonZeroUsize> for NonZeroU128

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 

impl<T, const N: usize> TryFrom<Box<[T], Global>> for Box<[T; N], Global>

impl<T, const N: usize> TryFrom<Rc<[T]>> for Rc<[T; N]>

impl<T, const N: usize> TryFrom<Arc<[T]>> for Arc<[T; N]>