Struct zkevm_keccak::util::eth_types::U256
[−]Expand description
Little-endian large integer type 256-bit unsigned integer.
Tuple Fields
0: [u64; 4]
Implementations
impl U256
impl U256
pub fn from_str_radix(txt: &str, radix: u32) -> Result<U256, FromStrRadixErr>
pub fn from_str_radix(txt: &str, radix: u32) -> Result<U256, FromStrRadixErr>
Converts a string slice in a given base to an integer. Only supports radixes of 10 and 16.
pub fn from_dec_str(value: &str) -> Result<U256, FromDecStrErr>
pub fn from_dec_str(value: &str) -> Result<U256, FromDecStrErr>
Convert from a decimal string.
pub fn as_u64(&self) -> u64
pub fn as_u64(&self) -> u64
Conversion to u64 with overflow checking
Panics
Panics if the number is larger than u64::max_value().
pub fn as_usize(&self) -> usize
pub fn as_usize(&self) -> usize
Conversion to usize with overflow checking
Panics
Panics if the number is larger than usize::max_value().
pub fn leading_zeros(&self) -> u32
pub fn leading_zeros(&self) -> u32
Returns the number of leading zeros in the binary representation of self.
pub fn trailing_zeros(&self) -> u32
pub fn trailing_zeros(&self) -> u32
Returns the number of trailing zeros in the binary representation of self.
pub fn to_big_endian(&self, bytes: &mut [u8])
pub fn to_big_endian(&self, bytes: &mut [u8])
Write to the slice in big-endian format.
pub fn to_little_endian(&self, bytes: &mut [u8])
pub fn to_little_endian(&self, bytes: &mut [u8])
Write to the slice in little-endian format.
pub fn integer_sqrt(&self) -> U256
pub fn integer_sqrt(&self) -> U256
Compute the highest n
such that n * n <= self
.
pub fn pow(self, expon: U256) -> U256
pub fn pow(self, expon: U256) -> U256
Fast exponentiation by squaring https://en.wikipedia.org/wiki/Exponentiation_by_squaring
Panics
Panics if the result overflows the type.
pub fn overflowing_pow(self, expon: U256) -> (U256, bool)
pub fn overflowing_pow(self, expon: U256) -> (U256, bool)
Fast exponentiation by squaring. Returns result and overflow flag.
pub fn checked_pow(self, expon: U256) -> Option<U256>
pub fn checked_pow(self, expon: U256) -> Option<U256>
Checked exponentiation. Returns None
if overflow occurred.
pub fn overflowing_add(self, other: U256) -> (U256, bool)
pub fn overflowing_add(self, other: U256) -> (U256, bool)
Addition which overflows and returns a flag if it does.
pub fn saturating_add(self, other: U256) -> U256
pub fn saturating_add(self, other: U256) -> U256
Addition which saturates at the maximum value (Self::MAX).
pub fn checked_add(self, other: U256) -> Option<U256>
pub fn checked_add(self, other: U256) -> Option<U256>
Checked addition. Returns None
if overflow occurred.
pub fn overflowing_sub(self, other: U256) -> (U256, bool)
pub fn overflowing_sub(self, other: U256) -> (U256, bool)
Subtraction which underflows and returns a flag if it does.
pub fn saturating_sub(self, other: U256) -> U256
pub fn saturating_sub(self, other: U256) -> U256
Subtraction which saturates at zero.
pub fn checked_sub(self, other: U256) -> Option<U256>
pub fn checked_sub(self, other: U256) -> Option<U256>
Checked subtraction. Returns None
if overflow occurred.
pub fn overflowing_mul(self, other: U256) -> (U256, bool)
pub fn overflowing_mul(self, other: U256) -> (U256, bool)
Multiply with overflow, returning a flag if it does.
pub fn saturating_mul(self, other: U256) -> U256
pub fn saturating_mul(self, other: U256) -> U256
Multiplication which saturates at the maximum value..
pub fn checked_mul(self, other: U256) -> Option<U256>
pub fn checked_mul(self, other: U256) -> Option<U256>
Checked multiplication. Returns None
if overflow occurred.
pub fn checked_div(self, other: U256) -> Option<U256>
pub fn checked_div(self, other: U256) -> Option<U256>
Checked division. Returns None
if other == 0
.
pub fn checked_rem(self, other: U256) -> Option<U256>
pub fn checked_rem(self, other: U256) -> Option<U256>
Checked modulus. Returns None
if other == 0
.
pub fn overflowing_neg(self) -> (U256, bool)
pub fn overflowing_neg(self) -> (U256, bool)
Negation with overflow.
pub fn checked_neg(self) -> Option<U256>
pub fn checked_neg(self) -> Option<U256>
Checked negation. Returns None
unless self == 0
.
pub fn from_big_endian(slice: &[u8]) -> U256
pub fn from_big_endian(slice: &[u8]) -> U256
Converts from big endian representation bytes in memory.
pub fn from_little_endian(slice: &[u8]) -> U256
pub fn from_little_endian(slice: &[u8]) -> U256
Converts from little endian representation bytes in memory.
impl U256
impl U256
Trait Implementations
impl AbiDecode for U256
impl AbiDecode for U256
impl AbiEncode for U256
impl AbiEncode for U256
impl AbiType for U256
impl AbiType for U256
fn param_type() -> ParamType
fn param_type() -> ParamType
impl AddAssign<U256> for U256
impl AddAssign<U256> for U256
fn add_assign(&mut self, other: U256)
fn add_assign(&mut self, other: U256)
+=
operation. Read moreimpl BitAndAssign<U256> for U256
impl BitAndAssign<U256> for U256
fn bitand_assign(&mut self, rhs: U256)
fn bitand_assign(&mut self, rhs: U256)
&=
operation. Read moreimpl BitOrAssign<U256> for U256
impl BitOrAssign<U256> for U256
fn bitor_assign(&mut self, rhs: U256)
fn bitor_assign(&mut self, rhs: U256)
|=
operation. Read moreimpl BitXorAssign<U256> for U256
impl BitXorAssign<U256> for U256
fn bitxor_assign(&mut self, rhs: U256)
fn bitxor_assign(&mut self, rhs: U256)
^=
operation. Read moreimpl Decodable for U256
impl Decodable for U256
impl Decode for U256
impl Decode for U256
fn decode<I>(input: &mut I) -> Result<U256, Error>where
I: Input,
fn decode<I>(input: &mut I) -> Result<U256, Error>where
I: Input,
fn skip<I>(input: &mut I) -> Result<(), Error>where
I: Input,
fn skip<I>(input: &mut I) -> Result<(), Error>where
I: Input,
fn encoded_fixed_size() -> Option<usize>
fn encoded_fixed_size() -> Option<usize>
impl<'de> Deserialize<'de> for U256
impl<'de> Deserialize<'de> for U256
fn deserialize<D>(
deserializer: D
) -> Result<U256, <D as Deserializer<'de>>::Error>where
D: Deserializer<'de>,
fn deserialize<D>(
deserializer: D
) -> Result<U256, <D as Deserializer<'de>>::Error>where
D: Deserializer<'de>,
impl<T> DivAssign<T> for U256where
T: Into<U256>,
impl<T> DivAssign<T> for U256where
T: Into<U256>,
fn div_assign(&mut self, other: T)
fn div_assign(&mut self, other: T)
/=
operation. Read moreimpl Encodable for U256
impl Encodable for U256
fn rlp_append(&self, s: &mut RlpStream)
fn rlp_append(&self, s: &mut RlpStream)
fn rlp_bytes(&self) -> BytesMut
fn rlp_bytes(&self) -> BytesMut
impl Encode for U256
impl Encode for U256
fn using_encoded<R, F>(&self, f: F) -> Rwhere
F: FnOnce(&[u8]) -> R,
fn using_encoded<R, F>(&self, f: F) -> Rwhere
F: FnOnce(&[u8]) -> R,
fn encode_to<T>(&self, dest: &mut T)where
T: Output + ?Sized,
fn encode_to<T>(&self, dest: &mut T)where
T: Output + ?Sized,
fn encoded_size(&self) -> usize
fn encoded_size(&self) -> usize
impl MaxEncodedLen for U256
impl MaxEncodedLen for U256
fn max_encoded_len() -> usize
fn max_encoded_len() -> usize
impl MulAssign<U256> for U256
impl MulAssign<U256> for U256
fn mul_assign(&mut self, other: U256)
fn mul_assign(&mut self, other: U256)
*=
operation. Read moreimpl MulAssign<i16> for U256
impl MulAssign<i16> for U256
fn mul_assign(&mut self, other: i16)
fn mul_assign(&mut self, other: i16)
*=
operation. Read moreimpl MulAssign<i32> for U256
impl MulAssign<i32> for U256
fn mul_assign(&mut self, other: i32)
fn mul_assign(&mut self, other: i32)
*=
operation. Read moreimpl MulAssign<i64> for U256
impl MulAssign<i64> for U256
fn mul_assign(&mut self, other: i64)
fn mul_assign(&mut self, other: i64)
*=
operation. Read moreimpl MulAssign<isize> for U256
impl MulAssign<isize> for U256
fn mul_assign(&mut self, other: isize)
fn mul_assign(&mut self, other: isize)
*=
operation. Read moreimpl MulAssign<u16> for U256
impl MulAssign<u16> for U256
fn mul_assign(&mut self, other: u16)
fn mul_assign(&mut self, other: u16)
*=
operation. Read moreimpl MulAssign<u32> for U256
impl MulAssign<u32> for U256
fn mul_assign(&mut self, other: u32)
fn mul_assign(&mut self, other: u32)
*=
operation. Read moreimpl MulAssign<u64> for U256
impl MulAssign<u64> for U256
fn mul_assign(&mut self, other: u64)
fn mul_assign(&mut self, other: u64)
*=
operation. Read moreimpl MulAssign<usize> for U256
impl MulAssign<usize> for U256
fn mul_assign(&mut self, other: usize)
fn mul_assign(&mut self, other: usize)
*=
operation. Read moreimpl Ord for U256
impl Ord for U256
1.21.0 · sourcefn max(self, other: Self) -> Selfwhere
Self: Sized,
fn max(self, other: Self) -> Selfwhere
Self: Sized,
1.21.0 · sourcefn min(self, other: Self) -> Selfwhere
Self: Sized,
fn min(self, other: Self) -> Selfwhere
Self: Sized,
1.50.0 · sourcefn clamp(self, min: Self, max: Self) -> Selfwhere
Self: Sized + PartialOrd<Self>,
fn clamp(self, min: Self, max: Self) -> Selfwhere
Self: Sized + PartialOrd<Self>,
impl PartialOrd<U256> for U256
impl PartialOrd<U256> for U256
impl<T> RemAssign<T> for U256where
T: Into<U256> + Copy,
impl<T> RemAssign<T> for U256where
T: Into<U256> + Copy,
fn rem_assign(&mut self, other: T)
fn rem_assign(&mut self, other: T)
%=
operation. Read moreimpl Serialize for U256
impl Serialize for U256
fn serialize<S>(
&self,
serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>where
S: Serializer,
fn serialize<S>(
&self,
serializer: S
) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>where
S: Serializer,
impl<T> ShlAssign<T> for U256where
T: Into<U256>,
impl<T> ShlAssign<T> for U256where
T: Into<U256>,
fn shl_assign(&mut self, shift: T)
fn shl_assign(&mut self, shift: T)
<<=
operation. Read moreimpl<T> ShrAssign<T> for U256where
T: Into<U256>,
impl<T> ShrAssign<T> for U256where
T: Into<U256>,
fn shr_assign(&mut self, shift: T)
fn shr_assign(&mut self, shift: T)
>>=
operation. Read moreimpl SubAssign<U256> for U256
impl SubAssign<U256> for U256
fn sub_assign(&mut self, other: U256)
fn sub_assign(&mut self, other: U256)
-=
operation. Read moresourceimpl ToBigEndian for U256
impl ToBigEndian for U256
sourcefn to_be_bytes(&self) -> [u8; 32]
fn to_be_bytes(&self) -> [u8; 32]
Encode the value as byte array in big endian.
sourceimpl ToLittleEndian for U256
impl ToLittleEndian for U256
sourcefn to_le_bytes(&self) -> [u8; 32]
fn to_le_bytes(&self) -> [u8; 32]
Encode the value as byte array in little endian.
impl Tokenizable for U256
impl Tokenizable for U256
fn from_token(token: Token) -> Result<U256, InvalidOutputType>
fn from_token(token: Token) -> Result<U256, InvalidOutputType>
Token
into expected type.fn into_token(self) -> Token
fn into_token(self) -> Token
impl AbiArrayType for U256
impl Copy for U256
impl EncodeLike<U256> for U256
impl Eq for U256
impl StructuralEq for U256
impl StructuralPartialEq for U256
impl TokenizableItem for U256
Auto Trait Implementations
impl RefUnwindSafe for U256
impl Send for U256
impl Sync for U256
impl Unpin for U256
impl UnwindSafe for U256
Blanket Implementations
impl<A, T> AsBits<T> for Awhere
A: AsRef<[T]>,
T: BitStore,
impl<A, T> AsBits<T> for Awhere
A: AsRef<[T]>,
T: BitStore,
fn as_bits<O>(&self) -> &BitSlice<T, O>where
O: BitOrder,
fn as_bits<O>(&self) -> &BitSlice<T, O>where
O: BitOrder,
self
as an immutable bit-slice region with the O
ordering.fn 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,
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
impl<T> DecodeAll for Twhere
T: Decode,
impl<T> DecodeAll for Twhere
T: Decode,
fn decode_all(input: &mut &[u8]) -> Result<T, Error>
fn decode_all(input: &mut &[u8]) -> Result<T, Error>
Self
and consume all of the given input data. Read moreimpl<T> DecodeLimit for Twhere
T: Decode,
impl<T> DecodeLimit for Twhere
T: Decode,
fn decode_all_with_depth_limit(limit: u32, input: &mut &[u8]) -> Result<T, Error>
fn decode_all_with_depth_limit(limit: u32, input: &mut &[u8]) -> Result<T, Error>
Self
and consume all of the given input data. Read morefn decode_with_depth_limit<I>(limit: u32, input: &mut I) -> Result<T, Error>where
I: Input,
fn decode_with_depth_limit<I>(limit: u32, input: &mut I) -> Result<T, Error>where
I: Input,
Self
with the given maximum recursion depth and advance input
by the number of
bytes consumed. Read moreimpl<T> Detokenize for Twhere
T: Tokenizable,
impl<T> Detokenize for Twhere
T: Tokenizable,
fn from_tokens(tokens: Vec<Token, Global>) -> Result<T, InvalidOutputType>
fn from_tokens(tokens: Vec<Token, Global>) -> Result<T, InvalidOutputType>
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,
self
to use its Binary
implementation when Debug
-formatted.fn fmt_display(self) -> FmtDisplay<Self>where
Self: Display,
fn fmt_display(self) -> FmtDisplay<Self>where
Self: Display,
fn fmt_lower_exp(self) -> FmtLowerExp<Self>where
Self: LowerExp,
fn fmt_lower_exp(self) -> FmtLowerExp<Self>where
Self: LowerExp,
fn fmt_lower_hex(self) -> FmtLowerHex<Self>where
Self: LowerHex,
fn fmt_lower_hex(self) -> FmtLowerHex<Self>where
Self: LowerHex,
fn fmt_octal(self) -> FmtOctal<Self>where
Self: Octal,
fn fmt_octal(self) -> FmtOctal<Self>where
Self: Octal,
self
to use its Octal
implementation when Debug
-formatted.fn fmt_pointer(self) -> FmtPointer<Self>where
Self: Pointer,
fn fmt_pointer(self) -> FmtPointer<Self>where
Self: Pointer,
fn fmt_upper_exp(self) -> FmtUpperExp<Self>where
Self: UpperExp,
fn fmt_upper_exp(self) -> FmtUpperExp<Self>where
Self: UpperExp,
fn fmt_upper_hex(self) -> FmtUpperHex<Self>where
Self: UpperHex,
fn fmt_upper_hex(self) -> FmtUpperHex<Self>where
Self: UpperHex,
fn fmt_list(self) -> FmtList<Self>where
&'a Self: for<'a> IntoIterator,
fn fmt_list(self) -> FmtList<Self>where
&'a Self: for<'a> IntoIterator,
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
impl<T> KeyedVec for Twhere
T: Codec,
impl<T> KeyedVec for Twhere
T: Codec,
fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8, Global>
fn to_keyed_vec(&self, prepend_key: &[u8]) -> Vec<u8, Global>
Self
prepended by given slice.impl<T> Pipe for Twhere
T: ?Sized,
impl<T> Pipe for Twhere
T: ?Sized,
fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> Rwhere
Self: Sized,
fn pipe<R>(self, func: impl FnOnce(Self) -> R) -> Rwhere
Self: Sized,
fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> Rwhere
R: 'a,
fn pipe_ref<'a, R>(&'a self, func: impl FnOnce(&'a Self) -> R) -> Rwhere
R: 'a,
self
and passes that borrow into the pipe function. Read morefn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> Rwhere
R: 'a,
fn pipe_ref_mut<'a, R>(&'a mut self, func: impl FnOnce(&'a mut Self) -> R) -> Rwhere
R: 'a,
self
and passes that borrow into the pipe function. Read morefn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> Rwhere
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow<'a, B, R>(&'a self, func: impl FnOnce(&'a B) -> R) -> Rwhere
Self: Borrow<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_borrow_mut<'a, B, R>(
&'a mut self,
func: impl FnOnce(&'a mut B) -> R
) -> Rwhere
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
) -> Rwhere
Self: BorrowMut<B>,
B: 'a + ?Sized,
R: 'a,
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> Rwhere
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_as_ref<'a, U, R>(&'a self, func: impl FnOnce(&'a U) -> R) -> Rwhere
Self: AsRef<U>,
U: 'a + ?Sized,
R: 'a,
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) -> Rwhere
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) -> Rwhere
Self: AsMut<U>,
U: 'a + ?Sized,
R: 'a,
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> Rwhere
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
fn pipe_deref<'a, T, R>(&'a self, func: impl FnOnce(&'a T) -> R) -> Rwhere
Self: Deref<Target = T>,
T: 'a + ?Sized,
R: 'a,
self
, then passes self.deref()
into the pipe function.impl<T> Pointable for T
impl<T> Pointable for T
impl<T> Tap for T
impl<T> Tap for T
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Selfwhere
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow<B>(self, func: impl FnOnce(&B)) -> Selfwhere
Self: Borrow<B>,
B: ?Sized,
Borrow<B>
of a value. Read morefn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Selfwhere
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut<B>(self, func: impl FnOnce(&mut B)) -> Selfwhere
Self: BorrowMut<B>,
B: ?Sized,
BorrowMut<B>
of a value. Read morefn tap_ref<R>(self, func: impl FnOnce(&R)) -> Selfwhere
Self: AsRef<R>,
R: ?Sized,
fn tap_ref<R>(self, func: impl FnOnce(&R)) -> Selfwhere
Self: AsRef<R>,
R: ?Sized,
AsRef<R>
view of a value. Read morefn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Selfwhere
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut<R>(self, func: impl FnOnce(&mut R)) -> Selfwhere
Self: AsMut<R>,
R: ?Sized,
AsMut<R>
view of a value. Read morefn tap_deref<T>(self, func: impl FnOnce(&T)) -> Selfwhere
Self: Deref<Target = T>,
T: ?Sized,
fn tap_deref<T>(self, func: impl FnOnce(&T)) -> Selfwhere
Self: Deref<Target = T>,
T: ?Sized,
Deref::Target
of a value. Read morefn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Selfwhere
Self: DerefMut<Target = T> + Deref,
T: ?Sized,
fn tap_deref_mut<T>(self, func: impl FnOnce(&mut T)) -> Selfwhere
Self: DerefMut<Target = T> + Deref,
T: ?Sized,
Deref::Target
of a value. Read morefn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
fn tap_dbg(self, func: impl FnOnce(&Self)) -> Self
.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
.tap_mut()
only in debug builds, and is erased in release
builds. Read morefn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Selfwhere
Self: Borrow<B>,
B: ?Sized,
fn tap_borrow_dbg<B>(self, func: impl FnOnce(&B)) -> Selfwhere
Self: Borrow<B>,
B: ?Sized,
.tap_borrow()
only in debug builds, and is erased in release
builds. Read morefn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Selfwhere
Self: BorrowMut<B>,
B: ?Sized,
fn tap_borrow_mut_dbg<B>(self, func: impl FnOnce(&mut B)) -> Selfwhere
Self: BorrowMut<B>,
B: ?Sized,
.tap_borrow_mut()
only in debug builds, and is erased in release
builds. Read morefn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Selfwhere
Self: AsRef<R>,
R: ?Sized,
fn tap_ref_dbg<R>(self, func: impl FnOnce(&R)) -> Selfwhere
Self: AsRef<R>,
R: ?Sized,
.tap_ref()
only in debug builds, and is erased in release
builds. Read morefn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Selfwhere
Self: AsMut<R>,
R: ?Sized,
fn tap_ref_mut_dbg<R>(self, func: impl FnOnce(&mut R)) -> Selfwhere
Self: AsMut<R>,
R: ?Sized,
.tap_ref_mut()
only in debug builds, and is erased in release
builds. Read more