Trait rustsec::package::checksum::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.

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Required methods

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

Performs the conversion.

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Implementations on Foreign Types

impl TryFrom<u32> for i32

type Error = TryFromIntError

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.

impl TryFrom<i32> for u16

type Error = TryFromIntError

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.

impl TryFrom<i128> for i8

type Error = TryFromIntError

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.

impl TryFrom<u64> for i64

type Error = TryFromIntError

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.

impl TryFrom<u8> for NonZeroU8

Attempts to convert u8 to NonZeroU8.

type Error = TryFromIntError

pub fn try_from(
    value: u8
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<u8>>::Error>

impl TryFrom<i128> for isize

type Error = TryFromIntError

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.

impl TryFrom<isize> for i16

type Error = TryFromIntError

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.

impl TryFrom<i64> for NonZeroI64

Attempts to convert i64 to NonZeroI64.

type Error = TryFromIntError

pub fn try_from(
    value: i64
) -> Result<NonZeroI64, <NonZeroI64 as TryFrom<i64>>::Error>

impl TryFrom<i64> for isize

type Error = TryFromIntError

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.

impl TryFrom<usize> for u8

type Error = TryFromIntError

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.

impl TryFrom<i128> for usize

type Error = TryFromIntError

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.

impl TryFrom<u64> for i8

type Error = TryFromIntError

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.

impl TryFrom<i64> for u8

type Error = TryFromIntError

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.

impl TryFrom<i32> for isize

type Error = TryFromIntError

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.

impl TryFrom<i64> for u128

type Error = TryFromIntError

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.

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<usize> for i16

type Error = TryFromIntError

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.

impl TryFrom<u32> for i16

type Error = TryFromIntError

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.

impl TryFrom<usize> for u16

type Error = TryFromIntError

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.

impl TryFrom<isize> for u32

type Error = TryFromIntError

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.

impl TryFrom<u32> for char

type Error = CharTryFromError

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

impl TryFrom<u128> for i64

type Error = TryFromIntError

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.

impl TryFrom<u16> for NonZeroU16

Attempts to convert u16 to NonZeroU16.

type Error = TryFromIntError

pub fn try_from(
    value: u16
) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<u16>>::Error>

impl TryFrom<u64> for u16

type Error = TryFromIntError

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.

impl TryFrom<u128> for u32

type Error = TryFromIntError

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.

impl TryFrom<u32> for u16

type Error = TryFromIntError

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.

impl TryFrom<i128> for u32

type Error = TryFromIntError

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.

impl TryFrom<u32> for usize

type Error = TryFromIntError

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.

impl TryFrom<i32> for u64

type Error = TryFromIntError

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.

impl TryFrom<u64> for isize

type Error = TryFromIntError

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.

impl TryFrom<i16> for i8

type Error = TryFromIntError

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.

impl TryFrom<i64> for u32

type Error = TryFromIntError

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.

impl TryFrom<u128> for u16

type Error = TryFromIntError

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.

impl TryFrom<i32> for i8

type Error = TryFromIntError

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.

impl TryFrom<u16> for isize

type Error = TryFromIntError

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.

impl TryFrom<u64> for u32

type Error = TryFromIntError

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.

impl TryFrom<usize> for i128

type Error = TryFromIntError

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.

impl TryFrom<usize> for i32

type Error = TryFromIntError

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.

impl TryFrom<i16> for u32

type Error = TryFromIntError

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.

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<u16> for u8

type Error = TryFromIntError

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.

impl TryFrom<u128> for u8

type Error = TryFromIntError

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.

impl TryFrom<isize> for i128

type Error = TryFromIntError

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.

impl TryFrom<u64> for usize

type Error = TryFromIntError

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.

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<i16> for u8

type Error = TryFromIntError

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.

impl TryFrom<usize> for u64

type Error = TryFromIntError

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.

impl TryFrom<u64> for i32

type Error = TryFromIntError

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.

impl TryFrom<usize> for u32

type Error = TryFromIntError

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.

impl TryFrom<u8> for i8

type Error = TryFromIntError

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.

impl TryFrom<i128> for NonZeroI128

Attempts to convert i128 to NonZeroI128.

type Error = TryFromIntError

pub fn try_from(
    value: i128
) -> Result<NonZeroI128, <NonZeroI128 as TryFrom<i128>>::Error>

impl TryFrom<i8> for usize

type Error = TryFromIntError

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.

impl TryFrom<i128> for i64

type Error = TryFromIntError

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.

impl TryFrom<i32> for u32

type Error = TryFromIntError

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.

impl TryFrom<i64> for u16

type Error = TryFromIntError

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.

impl TryFrom<u32> for isize

type Error = TryFromIntError

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.

impl TryFrom<isize> for u128

type Error = TryFromIntError

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.

impl TryFrom<u64> for NonZeroU64

Attempts to convert u64 to NonZeroU64.

type Error = TryFromIntError

pub fn try_from(
    value: u64
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<u64>>::Error>

impl TryFrom<i32> for u128

type Error = TryFromIntError

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.

impl TryFrom<i64> for usize

type Error = TryFromIntError

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.

impl TryFrom<i64> for i16

type Error = TryFromIntError

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.

impl TryFrom<i8> for u32

type Error = TryFromIntError

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.

impl TryFrom<u128> for NonZeroU128

Attempts to convert u128 to NonZeroU128.

type Error = TryFromIntError

pub fn try_from(
    value: u128
) -> Result<NonZeroU128, <NonZeroU128 as TryFrom<u128>>::Error>

impl TryFrom<usize> for u128

type Error = TryFromIntError

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.

impl TryFrom<i16> for NonZeroI16

Attempts to convert i16 to NonZeroI16.

type Error = TryFromIntError

pub fn try_from(
    value: i16
) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<i16>>::Error>

impl TryFrom<i8> for u16

type Error = TryFromIntError

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.

impl TryFrom<isize> for i64

type Error = TryFromIntError

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.

impl TryFrom<i32> for i16

type Error = TryFromIntError

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.

impl TryFrom<i32> for u8

type Error = TryFromIntError

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.

impl TryFrom<usize> for isize

type Error = TryFromIntError

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.

impl TryFrom<i32> for NonZeroI32

Attempts to convert i32 to NonZeroI32.

type Error = TryFromIntError

pub fn try_from(
    value: i32
) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<i32>>::Error>

impl TryFrom<usize> for i64

type Error = TryFromIntError

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.

impl TryFrom<u16> for i8

type Error = TryFromIntError

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.

impl TryFrom<i64> for i8

type Error = TryFromIntError

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.

impl TryFrom<i64> for i32

type Error = TryFromIntError

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.

impl TryFrom<isize> for usize

type Error = TryFromIntError

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.

impl TryFrom<u64> for i16

type Error = TryFromIntError

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.

impl TryFrom<isize> for i8

type Error = TryFromIntError

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.

impl TryFrom<isize> for u64

type Error = TryFromIntError

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.

impl TryFrom<u16> for i16

type Error = TryFromIntError

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.

impl TryFrom<i8> for u8

type Error = TryFromIntError

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.

impl TryFrom<i16> for u64

type Error = TryFromIntError

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.

impl TryFrom<u128> for i16

type Error = TryFromIntError

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.

impl TryFrom<i128> for i16

type Error = TryFromIntError

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.

impl TryFrom<i8> for NonZeroI8

Attempts to convert i8 to NonZeroI8.

type Error = TryFromIntError

pub fn try_from(
    value: i8
) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<i8>>::Error>

impl TryFrom<i8> for u128

type Error = TryFromIntError

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.

impl TryFrom<u32> for u8

type Error = TryFromIntError

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.

impl TryFrom<i128> for u128

type Error = TryFromIntError

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.

impl TryFrom<u32> for NonZeroU32

Attempts to convert u32 to NonZeroU32.

type Error = TryFromIntError

pub fn try_from(
    value: u32
) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<u32>>::Error>

impl TryFrom<isize> for u16

type Error = TryFromIntError

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.

impl TryFrom<i16> for u128

type Error = TryFromIntError

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.

impl TryFrom<u32> for i8

type Error = TryFromIntError

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.

impl TryFrom<i128> for u64

type Error = TryFromIntError

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.

impl TryFrom<i128> for u8

type Error = TryFromIntError

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.

impl TryFrom<u128> for usize

type Error = TryFromIntError

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.

impl TryFrom<u128> for u64

type Error = TryFromIntError

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.

impl TryFrom<u64> for u8

type Error = TryFromIntError

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.

impl TryFrom<i8> for u64

type Error = TryFromIntError

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.

impl TryFrom<i16> for usize

type Error = TryFromIntError

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.

impl TryFrom<u128> for isize

type Error = TryFromIntError

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.

impl TryFrom<u128> for i8

type Error = TryFromIntError

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.

impl TryFrom<isize> for i32

type Error = TryFromIntError

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.

impl TryFrom<usize> for NonZeroUsize

Attempts to convert usize to NonZeroUsize.

type Error = TryFromIntError

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

impl TryFrom<i128> for i32

type Error = TryFromIntError

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.

impl TryFrom<u128> for i32

type Error = TryFromIntError

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.

impl TryFrom<u128> for i128

type Error = TryFromIntError

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.

impl TryFrom<isize> for u8

type Error = TryFromIntError

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.

impl TryFrom<i16> for u16

type Error = TryFromIntError

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.

impl TryFrom<isize> for NonZeroIsize

Attempts to convert isize to NonZeroIsize.

type Error = TryFromIntError

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

impl TryFrom<usize> for i8

type Error = TryFromIntError

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.

impl TryFrom<i128> for u16

type Error = TryFromIntError

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.

impl TryFrom<i64> for u64

type Error = TryFromIntError

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.

impl TryFrom<i32> for usize

type Error = TryFromIntError

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.

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

type Error = Box<[T]>

pub fn try_from(
    boxed_slice: Box<[T]>
) -> Result<Box<[T; N]>, <Box<[T; N]> as TryFrom<Box<[T]>>>::Error>

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

type Error = Arc<[T]>

pub fn try_from(
    boxed_slice: Arc<[T]>
) -> Result<Arc<[T; N]>, <Arc<[T; N]> as TryFrom<Arc<[T]>>>::Error>

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

type Error = Vec<T>

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

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');

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

type Error = Rc<[T]>

pub fn try_from(
    boxed_slice: Rc<[T]>
) -> Result<Rc<[T; N]>, <Rc<[T; N]> as TryFrom<Rc<[T]>>>::Error>

impl TryFrom<usize> for Tier

type Error = Error

pub fn try_from(num: usize) -> Result<Tier, Error>

impl<'_> TryFrom<&'_ Key> for Dependency

type Error = Error

pub fn try_from(key: &Key) -> Result<Dependency, Error>

impl<'_> TryFrom<&'_ EncodableDependency> for Dependency

Note: this only works for ResolveVersion::V1 dependencies.

type Error = Error

pub fn try_from(
    raw_dependency: &EncodableDependency
) -> Result<Dependency, Error>

impl<T> TryFrom<Request<T>> for Request where
    T: Into<Body>, 

type Error = Error

pub fn try_from(req: Request<T>) -> Result<Request, Error>

impl<T> TryFrom<Request<T>> for Request where
    T: Into<Body>, 

type Error = Error

pub fn try_from(req: Request<T>) -> Result<Request, Error>

impl<'a> TryFrom<&'a [u8]> for Uri

type Error = InvalidUri

pub fn try_from(t: &'a [u8]) -> Result<Uri, <Uri as TryFrom<&'a [u8]>>::Error>

impl TryFrom<String> for HeaderValue

type Error = InvalidHeaderValue

pub fn try_from(
    t: String
) -> Result<HeaderValue, <HeaderValue as TryFrom<String>>::Error>

impl<'a> TryFrom<&'a [u8]> for StatusCode

type Error = InvalidStatusCode

pub fn try_from(
    t: &'a [u8]
) -> Result<StatusCode, <StatusCode as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a String> for HeaderValue

type Error = InvalidHeaderValue

pub fn try_from(
    s: &'a String
) -> Result<HeaderValue, <HeaderValue as TryFrom<&'a String>>::Error>

impl<'a> TryFrom<&'a [u8]> for HeaderName

type Error = InvalidHeaderName

pub fn try_from(
    s: &'a [u8]
) -> Result<HeaderName, <HeaderName as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a str> for Uri

type Error = InvalidUri

pub fn try_from(t: &'a str) -> Result<Uri, <Uri as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a Uri> for Uri

type Error = Error

pub fn try_from(src: &'a Uri) -> Result<Uri, <Uri as TryFrom<&'a Uri>>::Error>

impl TryFrom<u16> for StatusCode

type Error = InvalidStatusCode

pub fn try_from(
    t: u16
) -> Result<StatusCode, <StatusCode as TryFrom<u16>>::Error>

impl TryFrom<Parts> for Uri

type Error = InvalidUriParts

pub fn try_from(src: Parts) -> Result<Uri, <Uri as TryFrom<Parts>>::Error>

impl<'a, K, V, T> TryFrom<&'a HashMap<K, V, RandomState>> for HeaderMap<T> where
    K: Eq + Hash,
    T: TryFrom<&'a V>,
    HeaderName: TryFrom<&'a K>,
    <HeaderName as TryFrom<&'a K>>::Error: Into<Error>,
    <T as TryFrom<&'a V>>::Error: Into<Error>, 

Try to convert a HashMap into a HeaderMap.

Examples

use std::collections::HashMap;
use std::convert::TryInto;
use http::HeaderMap;

let mut map = HashMap::new();
map.insert("X-Custom-Header".to_string(), "my value".to_string());

let headers: HeaderMap = (&map).try_into().expect("valid headers");
assert_eq!(headers["X-Custom-Header"], "my value");

type Error = Error

pub fn try_from(
    c: &'a HashMap<K, V, RandomState>
) -> Result<HeaderMap<T>, <HeaderMap<T> as TryFrom<&'a HashMap<K, V, RandomState>>>::Error>

impl TryFrom<String> for Uri

type Error = InvalidUri

pub fn try_from(t: String) -> Result<Uri, <Uri as TryFrom<String>>::Error>

impl<'a> TryFrom<&'a String> for Uri

type Error = InvalidUri

pub fn try_from(
    t: &'a String
) -> Result<Uri, <Uri as TryFrom<&'a String>>::Error>

impl<'a> TryFrom<&'a [u8]> for Authority

type Error = InvalidUri

pub fn try_from(
    s: &'a [u8]
) -> Result<Authority, <Authority as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a String> for HeaderName

type Error = InvalidHeaderName

pub fn try_from(
    s: &'a String
) -> Result<HeaderName, <HeaderName as TryFrom<&'a String>>::Error>

impl<'a> TryFrom<&'a str> for PathAndQuery

type Error = InvalidUri

pub fn try_from(
    s: &'a str
) -> Result<PathAndQuery, <PathAndQuery as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a [u8]> for PathAndQuery

type Error = InvalidUri

pub fn try_from(
    s: &'a [u8]
) -> Result<PathAndQuery, <PathAndQuery as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a [u8]> for HeaderValue

type Error = InvalidHeaderValue

pub fn try_from(
    t: &'a [u8]
) -> Result<HeaderValue, <HeaderValue as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a str> for StatusCode

type Error = InvalidStatusCode

pub fn try_from(
    t: &'a str
) -> Result<StatusCode, <StatusCode as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a str> for Authority

type Error = InvalidUri

pub fn try_from(
    s: &'a str
) -> Result<Authority, <Authority as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a str> for Method

type Error = InvalidMethod

pub fn try_from(
    t: &'a str
) -> Result<Method, <Method as TryFrom<&'a str>>::Error>

impl TryFrom<Vec<u8>> for HeaderValue

type Error = InvalidHeaderValue

pub fn try_from(
    vec: Vec<u8>
) -> Result<HeaderValue, <HeaderValue as TryFrom<Vec<u8>>>::Error>

impl<'a> TryFrom<&'a str> for HeaderName

type Error = InvalidHeaderName

pub fn try_from(
    s: &'a str
) -> Result<HeaderName, <HeaderName as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a str> for Scheme

type Error = InvalidUri

pub fn try_from(
    s: &'a str
) -> Result<Scheme, <Scheme as TryFrom<&'a str>>::Error>

impl<'a> TryFrom<&'a [u8]> for Method

type Error = InvalidMethod

pub fn try_from(
    t: &'a [u8]
) -> Result<Method, <Method as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a [u8]> for Scheme

type Error = InvalidUri

pub fn try_from(
    s: &'a [u8]
) -> Result<Scheme, <Scheme as TryFrom<&'a [u8]>>::Error>

impl<'a> TryFrom<&'a str> for HeaderValue

type Error = InvalidHeaderValue

pub fn try_from(
    t: &'a str
) -> Result<HeaderValue, <HeaderValue as TryFrom<&'a str>>::Error>

impl TryFrom<TcpStream> for TcpStream

type Error = Error

pub fn try_from(
    stream: TcpStream
) -> Result<TcpStream, <TcpStream as TryFrom<TcpStream>>::Error>

Consumes stream, returning the tokio I/O object.

This is equivalent to TcpStream::from_std(stream).

impl TryFrom<TcpListener> for TcpListener

type Error = Error

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

Consumes value, returning the mio I/O object.

See PollEvented::into_inner for more details about resource deregistration that happens during the call.

impl TryFrom<TcpListener> for TcpListener

type Error = Error

pub fn try_from(
    stream: TcpListener
) -> Result<TcpListener, <TcpListener as TryFrom<TcpListener>>::Error>

Consumes stream, returning the tokio I/O object.

This is equivalent to TcpListener::from_std(stream).

impl TryFrom<TcpStream> for TcpStream

type Error = Error

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

Consumes value, returning the mio I/O object.

See PollEvented::into_inner for more details about resource deregistration that happens during the call.

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Implementors

impl TryFrom<EncodableLockfile> for Lockfile

type Error = Error

pub fn try_from(raw_lockfile: EncodableLockfile) -> Result<Lockfile, Error>

impl<'_> TryFrom<&'_ Value> for Checksum

type Error = Error

pub fn try_from(value: &Value) -> Result<Checksum, Error>

impl<'_> TryFrom<&'_ EncodablePackage> for Package

Note: this only works for ResolveVersion::V1 dependencies.

type Error = Error

pub fn try_from(raw_package: &EncodablePackage) -> Result<Package, Error>

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

type Error = Infallible

pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

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