Struct asn1_rs::TaggedValue
source · [−]Expand description
Helper object for creating FromBer
/FromDer
types for TAGGED OPTIONAL types
When parsing ContextSpecific
(the most common class), see TaggedExplicit
and
TaggedImplicit
alias types.
Notes
CLASS
must be between 0 and 4. See Class
for possible values for the CLASS
parameter.
Constants from this class can be used, but they must be wrapped in braces due to
Rust syntax for generics
(see example below).
Examples
To parse a [APPLICATION 0] EXPLICIT INTEGER
object:
use asn1_rs::{Class, Error, Explicit, FromBer, Integer, TaggedValue};
let bytes = &[0x60, 0x03, 0x2, 0x1, 0x2];
// If tagged object is present (and has expected tag), parsing succeeds:
let (_, tagged) =
TaggedValue::<Integer, Error, Explicit, {Class::APPLICATION}, 0>::from_ber(bytes)
.unwrap();
assert_eq!(tagged, TaggedValue::explicit(Integer::from(2)));
Implementations
sourceimpl<T, E, TagKind, const CLASS: u8, const TAG: u32> TaggedValue<T, E, TagKind, CLASS, TAG>
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> TaggedValue<T, E, TagKind, CLASS, TAG>
sourceimpl<T, E, const CLASS: u8, const TAG: u32> TaggedValue<T, E, Explicit, CLASS, TAG>
impl<T, E, const CLASS: u8, const TAG: u32> TaggedValue<T, E, Explicit, CLASS, TAG>
Trait Implementations
sourceimpl<T, E, TagKind, const CLASS: u8, const TAG: u32> AsRef<T> for TaggedValue<T, E, TagKind, CLASS, TAG>
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> AsRef<T> for TaggedValue<T, E, TagKind, CLASS, TAG>
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> CheckDerConstraints for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: CheckDerConstraints,
impl<'a, T, E, const CLASS: u8, const TAG: u32> CheckDerConstraints for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: CheckDerConstraints,
fn check_constraints(any: &Any<'_>) -> Result<()>
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> CheckDerConstraints for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: CheckDerConstraints,
T: Tagged,
impl<'a, T, E, const CLASS: u8, const TAG: u32> CheckDerConstraints for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: CheckDerConstraints,
T: Tagged,
fn check_constraints(any: &Any<'_>) -> Result<()>
sourceimpl<T: Debug, E: Debug, TagKind: Debug, const CLASS: u8, const TAG: u32> Debug for TaggedValue<T, E, TagKind, CLASS, TAG>
impl<T: Debug, E: Debug, TagKind: Debug, const CLASS: u8, const TAG: u32> Debug for TaggedValue<T, E, TagKind, CLASS, TAG>
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> FromDer<'a, E> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromDer<'a, E>,
E: From<Error>,
impl<'a, T, E, const CLASS: u8, const TAG: u32> FromDer<'a, E> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromDer<'a, E>,
E: From<Error>,
sourcefn from_der(bytes: &'a [u8]) -> ParseResult<'a, Self, E>
fn from_der(bytes: &'a [u8]) -> ParseResult<'a, Self, E>
Attempt to parse input bytes into a DER object (enforcing constraints)
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> FromDer<'a, E> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
impl<'a, T, E, const CLASS: u8, const TAG: u32> FromDer<'a, E> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
sourcefn from_der(bytes: &'a [u8]) -> ParseResult<'a, Self, E>
fn from_der(bytes: &'a [u8]) -> ParseResult<'a, Self, E>
Attempt to parse input bytes into a DER object (enforcing constraints)
sourceimpl<T: PartialEq, E: PartialEq, TagKind: PartialEq, const CLASS: u8, const TAG: u32> PartialEq<TaggedValue<T, E, TagKind, CLASS, TAG>> for TaggedValue<T, E, TagKind, CLASS, TAG>
impl<T: PartialEq, E: PartialEq, TagKind: PartialEq, const CLASS: u8, const TAG: u32> PartialEq<TaggedValue<T, E, TagKind, CLASS, TAG>> for TaggedValue<T, E, TagKind, CLASS, TAG>
sourcefn eq(&self, other: &TaggedValue<T, E, TagKind, CLASS, TAG>) -> bool
fn eq(&self, other: &TaggedValue<T, E, TagKind, CLASS, TAG>) -> bool
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
sourcefn ne(&self, other: &TaggedValue<T, E, TagKind, CLASS, TAG>) -> bool
fn ne(&self, other: &TaggedValue<T, E, TagKind, CLASS, TAG>) -> bool
This method tests for !=
.
sourceimpl<T, E, TagKind, const CLASS: u8, const TAG: u32> Tagged for TaggedValue<T, E, TagKind, CLASS, TAG>
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> Tagged for TaggedValue<T, E, TagKind, CLASS, TAG>
sourceimpl<T, E, const CLASS: u8, const TAG: u32> ToDer for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: ToDer,
impl<T, E, const CLASS: u8, const TAG: u32> ToDer for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: ToDer,
sourcefn to_der_len(&self) -> Result<usize>
fn to_der_len(&self) -> Result<usize>
Get the length of the object, when encoded Read more
sourcefn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER header to this writer.
sourcefn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER content (all except header) to this writer.
sourcefn to_der_vec(&self) -> SerializeResult<Vec<u8>>
fn to_der_vec(&self) -> SerializeResult<Vec<u8>>
Write the DER encoded representation to a newly allocated Vec<u8>
.
sourcefn to_der_vec_raw(&self) -> SerializeResult<Vec<u8>>
fn to_der_vec_raw(&self) -> SerializeResult<Vec<u8>>
Similar to using to_vec
, but uses provided values without changes.
This can generate an invalid encoding for a DER object. Read more
sourcefn write_der(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER encoded representation (header and content) into this writer. Read more
sourcefn write_der_raw(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_raw(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Similar to using to_der
, but uses provided values without changes.
This can generate an invalid encoding for a DER object. Read more
sourceimpl<T, E, const CLASS: u8, const TAG: u32> ToDer for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: ToDer,
impl<T, E, const CLASS: u8, const TAG: u32> ToDer for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: ToDer,
sourcefn to_der_len(&self) -> Result<usize>
fn to_der_len(&self) -> Result<usize>
Get the length of the object, when encoded Read more
sourcefn write_der(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER encoded representation (header and content) into this writer. Read more
sourcefn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_header(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER header to this writer.
sourcefn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_content(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Attempt to write the DER content (all except header) to this writer.
sourcefn to_der_vec(&self) -> SerializeResult<Vec<u8>>
fn to_der_vec(&self) -> SerializeResult<Vec<u8>>
Write the DER encoded representation to a newly allocated Vec<u8>
.
sourcefn to_der_vec_raw(&self) -> SerializeResult<Vec<u8>>
fn to_der_vec_raw(&self) -> SerializeResult<Vec<u8>>
Similar to using to_vec
, but uses provided values without changes.
This can generate an invalid encoding for a DER object. Read more
sourcefn write_der_raw(&self, writer: &mut dyn Write) -> SerializeResult<usize>
fn write_der_raw(&self, writer: &mut dyn Write) -> SerializeResult<usize>
Similar to using to_der
, but uses provided values without changes.
This can generate an invalid encoding for a DER object. Read more
sourceimpl<'a, 'b, T, E, const CLASS: u8, const TAG: u32> TryFrom<&'b Any<'a>> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromBer<'a, E>,
E: From<Error>,
impl<'a, 'b, T, E, const CLASS: u8, const TAG: u32> TryFrom<&'b Any<'a>> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromBer<'a, E>,
E: From<Error>,
sourceimpl<'a, 'b, E, T, const CLASS: u8, const TAG: u32> TryFrom<&'b Any<'a>> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
impl<'a, 'b, E, T, const CLASS: u8, const TAG: u32> TryFrom<&'b Any<'a>> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromBer<'a, E>,
E: From<Error>,
impl<'a, T, E, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, E, Explicit, CLASS, TAG> where
T: FromBer<'a, E>,
E: From<Error>,
sourceimpl<'a, T, E, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
impl<'a, T, E, const CLASS: u8, const TAG: u32> TryFrom<Any<'a>> for TaggedValue<T, E, Implicit, CLASS, TAG> where
T: TryFrom<Any<'a>, Error = E>,
T: Tagged,
E: From<Error>,
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> StructuralPartialEq for TaggedValue<T, E, TagKind, CLASS, TAG>
Auto Trait Implementations
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> RefUnwindSafe for TaggedValue<T, E, TagKind, CLASS, TAG> where
E: RefUnwindSafe,
T: RefUnwindSafe,
TagKind: RefUnwindSafe,
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> Send for TaggedValue<T, E, TagKind, CLASS, TAG> where
E: Send,
T: Send,
TagKind: Send,
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> Sync for TaggedValue<T, E, TagKind, CLASS, TAG> where
E: Sync,
T: Sync,
TagKind: Sync,
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> Unpin for TaggedValue<T, E, TagKind, CLASS, TAG> where
E: Unpin,
T: Unpin,
TagKind: Unpin,
impl<T, E, TagKind, const CLASS: u8, const TAG: u32> UnwindSafe for TaggedValue<T, E, TagKind, CLASS, TAG> where
E: UnwindSafe,
T: UnwindSafe,
TagKind: UnwindSafe,
Blanket Implementations
sourceimpl<A, T> AsBits<T> for A where
A: AsRef<[T]>,
T: BitStore,
impl<A, T> AsBits<T> for A where
A: AsRef<[T]>,
T: BitStore,
sourcefn as_bits<O>(&self) -> &BitSlice<T, O>ⓘNotable traits for &'_ mut BitSlice<T, O>impl<'_, T, O> Write for &'_ mut BitSlice<T, O> where
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField, impl<'_, T, O> Read for &'_ BitSlice<T, O> where
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField,
where
O: BitOrder,
fn as_bits<O>(&self) -> &BitSlice<T, O>ⓘNotable traits for &'_ mut BitSlice<T, O>impl<'_, T, O> Write for &'_ mut BitSlice<T, O> where
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField, impl<'_, T, O> Read for &'_ BitSlice<T, O> where
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField,
where
O: BitOrder,
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField, impl<'_, T, O> Read for &'_ BitSlice<T, O> where
T: BitStore,
O: BitOrder,
BitSlice<T, O>: BitField,
Views self
as an immutable bit-slice region with the O
ordering.
sourcefn try_as_bits<O>(&self) -> Result<&BitSlice<T, O>, BitSpanError<T>> where
O: BitOrder,
fn try_as_bits<O>(&self) -> Result<&BitSlice<T, O>, BitSpanError<T>> where
O: BitOrder,
Attempts to view self
as an immutable bit-slice region with the O
ordering. Read more
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
impl<T> FmtForward for T
impl<T> FmtForward for T
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
fn fmt_binary(self) -> FmtBinary<Self> where
Self: Binary,
Causes self
to use its Binary
implementation when Debug
-formatted. Read more
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
fn fmt_display(self) -> FmtDisplay<Self> where
Self: Display,
Causes self
to use its Display
implementation when
Debug
-formatted. Read more
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
fn fmt_lower_exp(self) -> FmtLowerExp<Self> where
Self: LowerExp,
Causes self
to use its LowerExp
implementation when
Debug
-formatted. Read more
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
fn fmt_lower_hex(self) -> FmtLowerHex<Self> where
Self: LowerHex,
Causes self
to use its LowerHex
implementation when
Debug
-formatted. Read more
fn fmt_octal(self) -> FmtOctal<Self> where
Self: Octal,
fn fmt_octal(self) -> FmtOctal<Self> where
Self: Octal,
Causes self
to use its Octal
implementation when Debug
-formatted. Read more
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
fn fmt_pointer(self) -> FmtPointer<Self> where
Self: Pointer,
Causes self
to use its Pointer
implementation when
Debug
-formatted. Read more
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
fn fmt_upper_exp(self) -> FmtUpperExp<Self> where
Self: UpperExp,
Causes self
to use its UpperExp
implementation when
Debug
-formatted. Read more
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
fn fmt_upper_hex(self) -> FmtUpperHex<Self> where
Self: UpperHex,
Causes self
to use its UpperHex
implementation when
Debug
-formatted. Read more
fn fmt_list(self) -> FmtList<Self> where
&'a Self: for<'a> IntoIterator,
fn fmt_list(self) -> FmtList<Self> where
&'a Self: for<'a> IntoIterator,
Formats each item in a sequence. Read more
impl<T> Pipe for T where
T: ?Sized,
impl<T> Pipe for T where
T: ?Sized,
fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> R
fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> R
Pipes by value. This is generally the method you want to use. Read more
fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> R where
R: 'a,
fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> R where
R: 'a,
Borrows self
and passes that borrow into the pipe function. Read more
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> R where
R: 'a,
Mutably borrows self
and passes that borrow into the pipe function. Read more
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> R where
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
Borrows self
, then passes self.borrow()
into the pipe function. Read more
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> R where
Self: BorrowMut<B>,
B: 'a + ?Sized,
R: 'a,
Mutably borrows self
, then passes self.borrow_mut()
into the pipe
function. Read more
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> R where
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
Borrows self
, then passes self.as_ref()
into the pipe function.
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_as_mut<'a, U, R>(&'a mut self, func: impl FnOnce(&'a mut U) -> R) -> R where
Self: AsMut<U>,
U: 'a + ?Sized,
R: 'a,
Mutably borrows self
, then passes self.as_mut()
into the pipe
function. Read more
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> R where
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
Borrows self
, then passes self.deref()
into the pipe function.
impl<T> Tap for T
impl<T> Tap for T
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Immutable access to the Borrow<B>
of a value. Read more
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Mutable access to the BorrowMut<B>
of a value. Read more
fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
Immutable access to the AsRef<R>
view of a value. Read more
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
Mutable access to the AsMut<R>
view of a value. Read more
fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self where
Self: Deref<Target = T>,
T: ?Sized,
fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Self where
Self: Deref<Target = T>,
T: ?Sized,
Immutable access to the Deref::Target
of a value. Read more
fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self where
Self: DerefMut<Target = T> + Deref,
T: ?Sized,
fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Self where
Self: DerefMut<Target = T> + Deref,
T: ?Sized,
Mutable access to the Deref::Target
of a value. Read more
fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
Calls .tap()
only in debug builds, and is erased in release builds.
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
fn tap_mut_dbg(self, func: impl FnOnce(&mut Self)) -> Self
Calls .tap_mut()
only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Self where
Self: Borrow<B>,
B: ?Sized,
Calls .tap_borrow()
only in debug builds, and is erased in release
builds. Read more
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Self where
Self: BorrowMut<B>,
B: ?Sized,
Calls .tap_borrow_mut()
only in debug builds, and is erased in release
builds. Read more
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Self where
Self: AsRef<R>,
R: ?Sized,
Calls .tap_ref()
only in debug builds, and is erased in release
builds. Read more
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Self where
Self: AsMut<R>,
R: ?Sized,
Calls .tap_ref_mut()
only in debug builds, and is erased in release
builds. Read more