pub trait TryFrom<T>: Sized {
type Error;
// Required method
fn try_from(value: T) -> Result<Self, Self::Error>;
}
mtls
only.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 values greater 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§
§impl TryFrom<&str> for ServerName
impl TryFrom<&str> for ServerName
Attempt to make a ServerName from a string by parsing it as a DNS name.
source§impl TryFrom<&String> for PathAndQuery
impl TryFrom<&String> for PathAndQuery
type Error = InvalidUri
source§impl TryFrom<Error> for InvalidFormatDescription
impl TryFrom<Error> for InvalidFormatDescription
type Error = DifferentVariant
source§impl TryFrom<Error> for ParseFromDescription
impl TryFrom<Error> for ParseFromDescription
type Error = DifferentVariant
source§impl TryFrom<Error> for TryFromParsed
impl TryFrom<Error> for TryFromParsed
type Error = DifferentVariant
source§impl TryFrom<Error> for ComponentRange
impl TryFrom<Error> for ComponentRange
type Error = DifferentVariant
source§impl TryFrom<Error> for ConversionRange
impl TryFrom<Error> for ConversionRange
type Error = DifferentVariant
source§impl TryFrom<Error> for DifferentVariant
impl TryFrom<Error> for DifferentVariant
type Error = DifferentVariant
source§impl TryFrom<Error> for InvalidVariant
impl TryFrom<Error> for InvalidVariant
type Error = DifferentVariant
source§impl TryFrom<Parse> for ParseFromDescription
impl TryFrom<Parse> for ParseFromDescription
type Error = DifferentVariant
source§impl TryFrom<Parse> for TryFromParsed
impl TryFrom<Parse> for TryFromParsed
type Error = DifferentVariant
source§impl TryFrom<TryFromParsed> for ComponentRange
impl TryFrom<TryFromParsed> for ComponentRange
type Error = DifferentVariant
source§impl TryFrom<BorrowedFormatItem<'_>> for Component
impl TryFrom<BorrowedFormatItem<'_>> for Component
type Error = DifferentVariant
source§impl TryFrom<OwnedFormatItem> for Component
impl TryFrom<OwnedFormatItem> for Component
type Error = DifferentVariant
source§impl TryFrom<OwnedFormatItem> for Vec<OwnedFormatItem, Global>
impl TryFrom<OwnedFormatItem> for Vec<OwnedFormatItem, Global>
type Error = DifferentVariant
1.59.0 · source§impl 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 · source§impl TryFrom<i16> for NonZeroI16
impl TryFrom<i16> for NonZeroI16
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<i32> for NonZeroI32
impl TryFrom<i32> for NonZeroI32
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<i64> for NonZeroI64
impl TryFrom<i64> for NonZeroI64
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<i128> for NonZeroI128
impl TryFrom<i128> for NonZeroI128
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<isize> for NonZeroIsize
impl TryFrom<isize> for NonZeroIsize
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<u16> for NonZeroU16
impl TryFrom<u16> for NonZeroU16
type Error = TryFromIntError
source§impl TryFrom<u16> for StatusCode
impl TryFrom<u16> for StatusCode
type Error = InvalidStatusCode
1.46.0 · source§impl TryFrom<u32> for NonZeroU32
impl TryFrom<u32> for NonZeroU32
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<u64> for NonZeroU64
impl TryFrom<u64> for NonZeroU64
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<u128> for NonZeroU128
impl TryFrom<u128> for NonZeroU128
type Error = TryFromIntError
1.46.0 · source§impl TryFrom<usize> for NonZeroUsize
impl TryFrom<usize> for NonZeroUsize
type Error = TryFromIntError
source§impl TryFrom<String> for HeaderName
impl TryFrom<String> for HeaderName
type Error = InvalidHeaderName
source§impl TryFrom<String> for HeaderValue
impl TryFrom<String> for HeaderValue
type Error = InvalidHeaderValue
source§impl TryFrom<String> for PathAndQuery
impl TryFrom<String> for PathAndQuery
type Error = InvalidUri
source§impl TryFrom<Vec<u8, Global>> for HeaderName
impl TryFrom<Vec<u8, Global>> for HeaderName
type Error = InvalidHeaderName
source§impl TryFrom<Vec<u8, Global>> for HeaderValue
impl TryFrom<Vec<u8, Global>> for HeaderValue
type Error = InvalidHeaderValue
1.49.0 · source§impl TryFrom<NonZeroI8> for NonZeroU16
impl TryFrom<NonZeroI8> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI8> for NonZeroU32
impl TryFrom<NonZeroI8> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI8> for NonZeroU64
impl TryFrom<NonZeroI8> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI8> for NonZeroU128
impl TryFrom<NonZeroI8> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI8> for NonZeroUsize
impl TryFrom<NonZeroI8> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroI8
impl TryFrom<NonZeroI16> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroU8
impl TryFrom<NonZeroI16> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroU16
impl TryFrom<NonZeroI16> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroU32
impl TryFrom<NonZeroI16> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroU64
impl TryFrom<NonZeroI16> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroU128
impl TryFrom<NonZeroI16> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI16> for NonZeroUsize
impl TryFrom<NonZeroI16> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroI8
impl TryFrom<NonZeroI32> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroI16
impl TryFrom<NonZeroI32> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroIsize
impl TryFrom<NonZeroI32> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroU8
impl TryFrom<NonZeroI32> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroU16
impl TryFrom<NonZeroI32> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroU32
impl TryFrom<NonZeroI32> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroU64
impl TryFrom<NonZeroI32> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroU128
impl TryFrom<NonZeroI32> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI32> for NonZeroUsize
impl TryFrom<NonZeroI32> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroI8
impl TryFrom<NonZeroI64> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroI16
impl TryFrom<NonZeroI64> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroI32
impl TryFrom<NonZeroI64> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroIsize
impl TryFrom<NonZeroI64> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroU8
impl TryFrom<NonZeroI64> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroU16
impl TryFrom<NonZeroI64> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroU32
impl TryFrom<NonZeroI64> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroU64
impl TryFrom<NonZeroI64> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroU128
impl TryFrom<NonZeroI64> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI64> for NonZeroUsize
impl TryFrom<NonZeroI64> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroI8
impl TryFrom<NonZeroI128> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroI16
impl TryFrom<NonZeroI128> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroI32
impl TryFrom<NonZeroI128> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroI64
impl TryFrom<NonZeroI128> for NonZeroI64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroIsize
impl TryFrom<NonZeroI128> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroU8
impl TryFrom<NonZeroI128> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroU16
impl TryFrom<NonZeroI128> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroU32
impl TryFrom<NonZeroI128> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroU64
impl TryFrom<NonZeroI128> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroU128
impl TryFrom<NonZeroI128> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroI128> for NonZeroUsize
impl TryFrom<NonZeroI128> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroI8
impl TryFrom<NonZeroIsize> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroI16
impl TryFrom<NonZeroIsize> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroI32
impl TryFrom<NonZeroIsize> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroI64
impl TryFrom<NonZeroIsize> for NonZeroI64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroI128
impl TryFrom<NonZeroIsize> for NonZeroI128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroU8
impl TryFrom<NonZeroIsize> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroU16
impl TryFrom<NonZeroIsize> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroU32
impl TryFrom<NonZeroIsize> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroU64
impl TryFrom<NonZeroIsize> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroU128
impl TryFrom<NonZeroIsize> for NonZeroU128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroIsize> for NonZeroUsize
impl TryFrom<NonZeroIsize> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU16> for NonZeroI8
impl TryFrom<NonZeroU16> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU16> for NonZeroI16
impl TryFrom<NonZeroU16> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU16> for NonZeroIsize
impl TryFrom<NonZeroU16> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU16> for NonZeroU8
impl TryFrom<NonZeroU16> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroI8
impl TryFrom<NonZeroU32> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroI16
impl TryFrom<NonZeroU32> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroI32
impl TryFrom<NonZeroU32> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroIsize
impl TryFrom<NonZeroU32> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroU8
impl TryFrom<NonZeroU32> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroU16
impl TryFrom<NonZeroU32> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU32> for NonZeroUsize
impl TryFrom<NonZeroU32> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroI8
impl TryFrom<NonZeroU64> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroI16
impl TryFrom<NonZeroU64> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroI32
impl TryFrom<NonZeroU64> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroI64
impl TryFrom<NonZeroU64> for NonZeroI64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroIsize
impl TryFrom<NonZeroU64> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroU8
impl TryFrom<NonZeroU64> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroU16
impl TryFrom<NonZeroU64> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroU32
impl TryFrom<NonZeroU64> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU64> for NonZeroUsize
impl TryFrom<NonZeroU64> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroI8
impl TryFrom<NonZeroU128> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroI16
impl TryFrom<NonZeroU128> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroI32
impl TryFrom<NonZeroU128> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroI64
impl TryFrom<NonZeroU128> for NonZeroI64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroI128
impl TryFrom<NonZeroU128> for NonZeroI128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroIsize
impl TryFrom<NonZeroU128> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroU8
impl TryFrom<NonZeroU128> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroU16
impl TryFrom<NonZeroU128> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroU32
impl TryFrom<NonZeroU128> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroU64
impl TryFrom<NonZeroU128> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroU128> for NonZeroUsize
impl TryFrom<NonZeroU128> for NonZeroUsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroI8
impl TryFrom<NonZeroUsize> for NonZeroI8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroI16
impl TryFrom<NonZeroUsize> for NonZeroI16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroI32
impl TryFrom<NonZeroUsize> for NonZeroI32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroI64
impl TryFrom<NonZeroUsize> for NonZeroI64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroI128
impl TryFrom<NonZeroUsize> for NonZeroI128
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroIsize
impl TryFrom<NonZeroUsize> for NonZeroIsize
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroU8
impl TryFrom<NonZeroUsize> for NonZeroU8
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroU16
impl TryFrom<NonZeroUsize> for NonZeroU16
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroU32
impl TryFrom<NonZeroUsize> for NonZeroU32
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroU64
impl TryFrom<NonZeroUsize> for NonZeroU64
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZeroUsize> for NonZeroU128
impl TryFrom<NonZeroUsize> for NonZeroU128
type Error = TryFromIntError
source§impl TryFrom<NonZeroUsize> for Alignment
impl TryFrom<NonZeroUsize> for Alignment
type Error = TryFromIntError
source§impl TryFrom<TcpListener> for TcpListener
impl TryFrom<TcpListener> for TcpListener
source§impl TryFrom<UnixDatagram> for UnixDatagram
impl TryFrom<UnixDatagram> for UnixDatagram
source§impl TryFrom<UnixListener> for UnixListener
impl TryFrom<UnixListener> for UnixListener
source§impl TryFrom<UnixStream> for UnixStream
impl TryFrom<UnixStream> for UnixStream
source§impl TryFrom<SystemTime> for webpki::time::Time
impl TryFrom<SystemTime> for webpki::time::Time
type Error = SystemTimeError
source§impl TryFrom<Parsed> for OffsetDateTime
impl TryFrom<Parsed> for OffsetDateTime
source§impl TryFrom<Parsed> for PrimitiveDateTime
impl TryFrom<Parsed> for PrimitiveDateTime
§impl TryFrom<PlainMessage> for Message
impl TryFrom<PlainMessage> for Message
Parses a plaintext message into a well-typed [Message
].
A [PlainMessage
] must contain plaintext content. Encrypted content should be stored in an
[OpaqueMessage
] and decrypted before being stored into a [PlainMessage
].
source§impl<'a> TryFrom<&'a str> for HeaderName
impl<'a> TryFrom<&'a str> for HeaderName
type Error = InvalidHeaderName
source§impl<'a> TryFrom<&'a str> for HeaderValue
impl<'a> TryFrom<&'a str> for HeaderValue
type Error = InvalidHeaderValue
source§impl<'a> TryFrom<&'a str> for StatusCode
impl<'a> TryFrom<&'a str> for StatusCode
type Error = InvalidStatusCode
source§impl<'a> TryFrom<&'a str> for PathAndQuery
impl<'a> TryFrom<&'a str> for PathAndQuery
type Error = InvalidUri
source§impl<'a> TryFrom<&'a String> for HeaderName
impl<'a> TryFrom<&'a String> for HeaderName
type Error = InvalidHeaderName
source§impl<'a> TryFrom<&'a String> for HeaderValue
impl<'a> TryFrom<&'a String> for HeaderValue
type Error = InvalidHeaderValue
source§impl<'a> TryFrom<&'a [u8]> for HeaderName
impl<'a> TryFrom<&'a [u8]> for HeaderName
type Error = InvalidHeaderName
source§impl<'a> TryFrom<&'a [u8]> for HeaderValue
impl<'a> TryFrom<&'a [u8]> for HeaderValue
type Error = InvalidHeaderValue
source§impl<'a> TryFrom<&'a [u8]> for StatusCode
impl<'a> TryFrom<&'a [u8]> for StatusCode
type Error = InvalidStatusCode
source§impl<'a> TryFrom<&'a [u8]> for PathAndQuery
impl<'a> TryFrom<&'a [u8]> for PathAndQuery
type Error = InvalidUri
source§impl<'a> TryFrom<BorrowedFormatItem<'a>> for &[BorrowedFormatItem<'a>]
impl<'a> TryFrom<BorrowedFormatItem<'a>> for &[BorrowedFormatItem<'a>]
type Error = DifferentVariant
source§impl<'a> TryFrom<Vec<u8, Global>> for PathAndQuery
impl<'a> TryFrom<Vec<u8, Global>> for PathAndQuery
type Error = InvalidUri
source§impl<'a, K, V, T> TryFrom<&'a HashMap<K, V, RandomState>> for HeaderMap<T>where
K: Eq + Hash,
HeaderName: TryFrom<&'a K>,
<HeaderName as TryFrom<&'a K>>::Error: Into<Error>,
T: TryFrom<&'a V>,
<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, HeaderName: TryFrom<&'a K>, <HeaderName as TryFrom<&'a K>>::Error: Into<Error>, T: TryFrom<&'a V>, <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");
§impl<'a, T, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, Explicit, CLASS, TAG>where
T: FromBer<'a>,
impl<'a, T, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, Explicit, CLASS, TAG>where T: FromBer<'a>,
§impl<'a, T, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, Implicit, CLASS, TAG>where
T: TryFrom<Any<'a>, Error = Error> + Tagged,
impl<'a, T, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, Implicit, CLASS, TAG>where T: TryFrom<Any<'a>, Error = Error> + Tagged,
source§impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N]
impl<'a, T, const N: usize> TryFrom<&'a [T]> for &'a [T; N]
Tries to create an array ref &[T; N]
from a slice ref &[T]
. Succeeds if
slice.len() == N
.
let bytes: [u8; 3] = [1, 0, 2];
let bytes_head: &[u8; 2] = <&[u8; 2]>::try_from(&bytes[0..2]).unwrap();
assert_eq!(1, u16::from_le_bytes(*bytes_head));
let bytes_tail: &[u8; 2] = bytes[1..3].try_into().unwrap();
assert_eq!(512, u16::from_le_bytes(*bytes_tail));
type Error = TryFromSliceError
source§impl<'a, T, const N: usize> TryFrom<&'a mut [T]> for &'a mut [T; N]
impl<'a, T, const N: usize> TryFrom<&'a mut [T]> for &'a mut [T; N]
Tries to create a mutable array ref &mut [T; N]
from a mutable slice ref
&mut [T]
. Succeeds if slice.len() == N
.
let mut bytes: [u8; 3] = [1, 0, 2];
let bytes_head: &mut [u8; 2] = <&mut [u8; 2]>::try_from(&mut bytes[0..2]).unwrap();
assert_eq!(1, u16::from_le_bytes(*bytes_head));
let bytes_tail: &mut [u8; 2] = (&mut bytes[1..3]).try_into().unwrap();
assert_eq!(512, u16::from_le_bytes(*bytes_tail));
type Error = TryFromSliceError
source§impl<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,
Tries to create an array [T; N]
by copying from a slice &[T]
. Succeeds if
slice.len() == N
.
let bytes: [u8; 3] = [1, 0, 2];
let bytes_head: [u8; 2] = <[u8; 2]>::try_from(&bytes[0..2]).unwrap();
assert_eq!(1, u16::from_le_bytes(bytes_head));
let bytes_tail: [u8; 2] = bytes[1..3].try_into().unwrap();
assert_eq!(512, u16::from_le_bytes(bytes_tail));
type Error = TryFromSliceError
1.59.0 · source§impl<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,
Tries to create an array [T; N]
by copying from a mutable slice &mut [T]
.
Succeeds if slice.len() == N
.
let mut bytes: [u8; 3] = [1, 0, 2];
let bytes_head: [u8; 2] = <[u8; 2]>::try_from(&mut bytes[0..2]).unwrap();
assert_eq!(1, u16::from_le_bytes(bytes_head));
let bytes_tail: [u8; 2] = (&mut bytes[1..3]).try_into().unwrap();
assert_eq!(512, u16::from_le_bytes(bytes_tail));