Expand description
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
impliesTryInto
<U> for T
try_from
is reflexive, which means thatTryFrom<T> for T
is implemented and cannot fail – the associatedError
type for callingT::try_from()
on a value of typeT
isInfallible
. When the!
type is stabilizedInfallible
and!
will be equivalent.
TryFrom<T>
can be implemented as follows:
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
>
:
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());
Required Associated Types
Required Methods
Implementors
1.59.0 · sourceimpl TryFrom<char> for u8
impl TryFrom<char> for u8
Map char
with code point in U+0000..=U+00FF to byte in 0x00..=0xFF with same value, failing
if the code point is greater than U+00FF.
See impl From<u8> for char
for details on the encoding.
type Error = TryFromCharError
1.46.0 · sourceimpl TryFrom<i16> for NonZeroI16
impl TryFrom<i16> for NonZeroI16
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<i32> for NonZeroI32
impl TryFrom<i32> for NonZeroI32
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<i64> for NonZeroI64
impl TryFrom<i64> for NonZeroI64
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<i128> for NonZeroI128
impl TryFrom<i128> for NonZeroI128
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<isize> for NonZeroIsize
impl TryFrom<isize> for NonZeroIsize
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<u16> for NonZeroU16
impl TryFrom<u16> for NonZeroU16
type Error = TryFromIntError
sourceimpl TryFrom<u16> for StatusCode
impl TryFrom<u16> for StatusCode
type Error = InvalidStatusCode
1.46.0 · sourceimpl TryFrom<u32> for NonZeroU32
impl TryFrom<u32> for NonZeroU32
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<u64> for NonZeroU64
impl TryFrom<u64> for NonZeroU64
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<u128> for NonZeroU128
impl TryFrom<u128> for NonZeroU128
type Error = TryFromIntError
1.46.0 · sourceimpl TryFrom<usize> for NonZeroUsize
impl TryFrom<usize> for NonZeroUsize
type Error = TryFromIntError
impl TryFrom<UnixDatagram> for UnixDatagram
impl TryFrom<UnixDatagram> for UnixDatagram
impl TryFrom<UnixListener> for UnixListener
impl TryFrom<UnixListener> for UnixListener
sourceimpl TryFrom<Duration> for FutureInstant
impl TryFrom<Duration> for FutureInstant
type Error = FutureInstantOutOfRange
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroI8
impl TryFrom<NonZeroUsize> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroI16
impl TryFrom<NonZeroUsize> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroI32
impl TryFrom<NonZeroUsize> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroI64
impl TryFrom<NonZeroUsize> for NonZeroI64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroI128
impl TryFrom<NonZeroUsize> for NonZeroI128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroIsize
impl TryFrom<NonZeroUsize> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU8
impl TryFrom<NonZeroUsize> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU16
impl TryFrom<NonZeroUsize> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU32
impl TryFrom<NonZeroUsize> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU64
impl TryFrom<NonZeroUsize> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU128
impl TryFrom<NonZeroUsize> for NonZeroU128
type Error = TryFromIntError
impl TryFrom<UnixStream> for UnixStream
impl TryFrom<UnixStream> for UnixStream
1.49.0 · sourceimpl TryFrom<NonZeroI8> for NonZeroUsize
impl TryFrom<NonZeroI8> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI8> for NonZeroU16
impl TryFrom<NonZeroI8> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI8> for NonZeroU32
impl TryFrom<NonZeroI8> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI8> for NonZeroU64
impl TryFrom<NonZeroI8> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI8> for NonZeroU128
impl TryFrom<NonZeroI8> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroUsize
impl TryFrom<NonZeroI16> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroI8
impl TryFrom<NonZeroI16> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU8
impl TryFrom<NonZeroI16> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU16
impl TryFrom<NonZeroI16> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU32
impl TryFrom<NonZeroI16> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU64
impl TryFrom<NonZeroI16> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU128
impl TryFrom<NonZeroI16> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroUsize
impl TryFrom<NonZeroI32> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroI8
impl TryFrom<NonZeroI32> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroI16
impl TryFrom<NonZeroI32> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroIsize
impl TryFrom<NonZeroI32> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU8
impl TryFrom<NonZeroI32> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU16
impl TryFrom<NonZeroI32> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU32
impl TryFrom<NonZeroI32> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU64
impl TryFrom<NonZeroI32> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU128
impl TryFrom<NonZeroI32> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroUsize
impl TryFrom<NonZeroI64> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroI8
impl TryFrom<NonZeroI64> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroI16
impl TryFrom<NonZeroI64> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroI32
impl TryFrom<NonZeroI64> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroIsize
impl TryFrom<NonZeroI64> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU8
impl TryFrom<NonZeroI64> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU16
impl TryFrom<NonZeroI64> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU32
impl TryFrom<NonZeroI64> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU64
impl TryFrom<NonZeroI64> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU128
impl TryFrom<NonZeroI64> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroUsize
impl TryFrom<NonZeroI128> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroI8
impl TryFrom<NonZeroI128> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroI16
impl TryFrom<NonZeroI128> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroI32
impl TryFrom<NonZeroI128> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroI64
impl TryFrom<NonZeroI128> for NonZeroI64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroIsize
impl TryFrom<NonZeroI128> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU8
impl TryFrom<NonZeroI128> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU16
impl TryFrom<NonZeroI128> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU32
impl TryFrom<NonZeroI128> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU64
impl TryFrom<NonZeroI128> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU128
impl TryFrom<NonZeroI128> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroUsize
impl TryFrom<NonZeroIsize> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroI8
impl TryFrom<NonZeroIsize> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroI16
impl TryFrom<NonZeroIsize> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroI32
impl TryFrom<NonZeroIsize> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroI64
impl TryFrom<NonZeroIsize> for NonZeroI64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroI128
impl TryFrom<NonZeroIsize> for NonZeroI128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU8
impl TryFrom<NonZeroIsize> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU16
impl TryFrom<NonZeroIsize> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU32
impl TryFrom<NonZeroIsize> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU64
impl TryFrom<NonZeroIsize> for NonZeroU64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU128
impl TryFrom<NonZeroIsize> for NonZeroU128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU16> for NonZeroI8
impl TryFrom<NonZeroU16> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU16> for NonZeroI16
impl TryFrom<NonZeroU16> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU16> for NonZeroIsize
impl TryFrom<NonZeroU16> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU16> for NonZeroU8
impl TryFrom<NonZeroU16> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroUsize
impl TryFrom<NonZeroU32> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroI8
impl TryFrom<NonZeroU32> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroI16
impl TryFrom<NonZeroU32> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroI32
impl TryFrom<NonZeroU32> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroIsize
impl TryFrom<NonZeroU32> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroU8
impl TryFrom<NonZeroU32> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroU16
impl TryFrom<NonZeroU32> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroUsize
impl TryFrom<NonZeroU64> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroI8
impl TryFrom<NonZeroU64> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroI16
impl TryFrom<NonZeroU64> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroI32
impl TryFrom<NonZeroU64> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroI64
impl TryFrom<NonZeroU64> for NonZeroI64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroIsize
impl TryFrom<NonZeroU64> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroU8
impl TryFrom<NonZeroU64> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroU16
impl TryFrom<NonZeroU64> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroU32
impl TryFrom<NonZeroU64> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroUsize
impl TryFrom<NonZeroU128> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroI8
impl TryFrom<NonZeroU128> for NonZeroI8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroI16
impl TryFrom<NonZeroU128> for NonZeroI16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroI32
impl TryFrom<NonZeroU128> for NonZeroI32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroI64
impl TryFrom<NonZeroU128> for NonZeroI64
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroI128
impl TryFrom<NonZeroU128> for NonZeroI128
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroIsize
impl TryFrom<NonZeroU128> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroU8
impl TryFrom<NonZeroU128> for NonZeroU8
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroU16
impl TryFrom<NonZeroU128> for NonZeroU16
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroU32
impl TryFrom<NonZeroU128> for NonZeroU32
type Error = TryFromIntError
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroU64
impl TryFrom<NonZeroU128> for NonZeroU64
type Error = TryFromIntError
sourceimpl TryFrom<String> for GoodItemName
impl TryFrom<String> for GoodItemName
type Error = LibraryLoadError
sourceimpl TryFrom<String> for HeaderName
impl TryFrom<String> for HeaderName
type Error = InvalidHeaderName
sourceimpl TryFrom<String> for HeaderValue
impl TryFrom<String> for HeaderValue
type Error = InvalidHeaderValue
sourceimpl TryFrom<String> for PathAndQuery
impl TryFrom<String> for PathAndQuery
type Error = InvalidUri
sourceimpl TryFrom<Vec<u8, Global>> for HeaderName
impl TryFrom<Vec<u8, Global>> for HeaderName
type Error = InvalidHeaderName
sourceimpl TryFrom<Vec<u8, Global>> for HeaderValue
impl TryFrom<Vec<u8, Global>> for HeaderValue
type Error = InvalidHeaderValue
impl TryFrom<Vec<u32, Global>> for FakeTimeSpec
impl TryFrom<Vec<u32, Global>> for FakeTimeSpec
type Error = InvalidFakeTime
impl TryFrom<TcpListener> for TcpListener
impl TryFrom<TcpListener> for TcpListener
sourceimpl TryFrom<IOccultIlk_Compat> for IOccultIlk
impl TryFrom<IOccultIlk_Compat> for IOccultIlk
type Error = Infallible
sourceimpl<'_> TryFrom<&str> for PresentationLayout
impl<'_> TryFrom<&str> for PresentationLayout
type Error = ParseError
impl<'_> TryFrom<&str> for LogSpecification
impl<'_> TryFrom<&str> for LogSpecification
type Error = FlexiLoggerError
impl<'_> TryFrom<&str> for ZCoord
impl<'_> TryFrom<&str> for ZCoord
type Error = ParseError
sourceimpl<'_> TryFrom<&ColourSpec> for Html
impl<'_> TryFrom<&ColourSpec> for Html
type Error = UnsupportedColourSpec
impl<'_> TryFrom<&String> for LogSpecification
impl<'_> TryFrom<&String> for LogSpecification
type Error = FlexiLoggerError
sourceimpl<'_> TryFrom<&String> for PathAndQuery
impl<'_> TryFrom<&String> for PathAndQuery
type Error = InvalidUri
impl<'_, T, A> TryFrom<&[T]> for ArrayVec<A> where
T: Clone + Default,
A: Array<Item = T>,
impl<'_, T, A> TryFrom<&[T]> for ArrayVec<A> where
T: Clone + Default,
A: Array<Item = T>,
type Error = TryFromSliceError
sourceimpl<'_, T, const CAP: usize> TryFrom<&[T]> for otter_api_tests::ArrayVec<T, CAP> where
T: Clone,
impl<'_, T, const CAP: usize> TryFrom<&[T]> for otter_api_tests::ArrayVec<T, CAP> where
T: Clone,
Try to create an ArrayVec
from a slice. This will return an error if the slice was too big to
fit.
use arrayvec::ArrayVec;
use std::convert::TryInto as _;
let array: ArrayVec<_, 4> = (&[1, 2, 3] as &[_]).try_into().unwrap();
assert_eq!(array.len(), 3);
assert_eq!(array.capacity(), 4);
type Error = CapacityError<()>
sourceimpl<'_, T, const N: usize> TryFrom<&[T]> for [T; N] where
T: Copy,
impl<'_, T, const N: usize> TryFrom<&[T]> for [T; N] where
T: Copy,
type Error = TryFromSliceError
1.59.0 · sourceimpl<'_, T, const N: usize> TryFrom<&mut [T]> for [T; N] where
T: Copy,
impl<'_, T, const N: usize> TryFrom<&mut [T]> for [T; N] where
T: Copy,
type Error = TryFromSliceError
sourceimpl<'a> TryFrom<&'a str> for HeaderName
impl<'a> TryFrom<&'a str> for HeaderName
type Error = InvalidHeaderName
sourceimpl<'a> TryFrom<&'a str> for HeaderValue
impl<'a> TryFrom<&'a str> for HeaderValue
type Error = InvalidHeaderValue
sourceimpl<'a> TryFrom<&'a str> for StatusCode
impl<'a> TryFrom<&'a str> for StatusCode
type Error = InvalidStatusCode
sourceimpl<'a> TryFrom<&'a str> for PathAndQuery
impl<'a> TryFrom<&'a str> for PathAndQuery
type Error = InvalidUri
sourceimpl<'a> TryFrom<&'a String> for HeaderName
impl<'a> TryFrom<&'a String> for HeaderName
type Error = InvalidHeaderName
sourceimpl<'a> TryFrom<&'a String> for HeaderValue
impl<'a> TryFrom<&'a String> for HeaderValue
type Error = InvalidHeaderValue
sourceimpl<'a> TryFrom<&'a [u8]> for HeaderName
impl<'a> TryFrom<&'a [u8]> for HeaderName
type Error = InvalidHeaderName
sourceimpl<'a> TryFrom<&'a [u8]> for HeaderValue
impl<'a> TryFrom<&'a [u8]> for HeaderValue
type Error = InvalidHeaderValue
sourceimpl<'a> TryFrom<&'a [u8]> for StatusCode
impl<'a> TryFrom<&'a [u8]> for StatusCode
type Error = InvalidStatusCode
sourceimpl<'a> TryFrom<&'a [u8]> for PathAndQuery
impl<'a> TryFrom<&'a [u8]> for PathAndQuery
type Error = InvalidUri
sourceimpl<'a> TryFrom<Vec<u8, Global>> for PathAndQuery
impl<'a> TryFrom<Vec<u8, Global>> for PathAndQuery
type Error = InvalidUri
sourceimpl<'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>,
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");