Trait OptionCheckedSub 

pub trait OptionCheckedSub<Rhs = Self, InnerRhs = Rhs> {
    type Output;

    // Required method
    fn opt_checked_sub(self, rhs: Rhs) -> Result<Option<Self::Output>, Error>;
}

Trait for values and Options checked substraction.

Implementing this trait leads to the following auto-implementations:

• OptionCheckedSub<Option<InnerRhs>> for T.
• OptionCheckedSub<Rhs> for Option<T>.
• OptionCheckedSub<Option<InnerRhs>> for Option<T>.
• … and some variants with references.

Note that since the std library doesn’t define any CheckedSub trait, users must provide the base implementation for the inner type.

Required Associated Types

type Output

The resulting inner type after applying the substraction.

Required Methods

fn opt_checked_sub(self, rhs: Rhs) -> Result<Option<Self::Output>, Error>

Computes the checked substraction.

• Returns Ok(Some(result)) if result could be computed.
• Returns Ok(None) if at least one argument is None.
• Returns Err(Error::Overflow) if an overflow occured.

Implementations on Foreign Types

impl OptionCheckedSub for i8

type Output = i8

fn opt_checked_sub( self, rhs: i8, ) -> Result<Option<<i8 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for i16

type Output = i16

fn opt_checked_sub( self, rhs: i16, ) -> Result<Option<<i16 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for i32

type Output = i32

fn opt_checked_sub( self, rhs: i32, ) -> Result<Option<<i32 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for i64

type Output = i64

fn opt_checked_sub( self, rhs: i64, ) -> Result<Option<<i64 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for i128

type Output = i128

fn opt_checked_sub( self, rhs: i128, ) -> Result<Option<<i128 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for u8

type Output = u8

fn opt_checked_sub( self, rhs: u8, ) -> Result<Option<<u8 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for u16

type Output = u16

fn opt_checked_sub( self, rhs: u16, ) -> Result<Option<<u16 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for u32

type Output = u32

fn opt_checked_sub( self, rhs: u32, ) -> Result<Option<<u32 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for u64

type Output = u64

fn opt_checked_sub( self, rhs: u64, ) -> Result<Option<<u64 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for u128

type Output = u128

fn opt_checked_sub( self, rhs: u128, ) -> Result<Option<<u128 as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub for Duration

type Output = Duration

fn opt_checked_sub( self, rhs: Duration, ) -> Result<Option<<Duration as OptionCheckedSub>::Output>, Error>

impl OptionCheckedSub<Signed<u32>> for u32

type Output = Signed<u32>

fn opt_checked_sub( self, rhs: Signed<u32>, ) -> Result<Option<Self::Output>, Error>

impl OptionCheckedSub<Signed<u64>> for u64

type Output = Signed<u64>

fn opt_checked_sub( self, rhs: Signed<u64>, ) -> Result<Option<Self::Output>, Error>

impl OptionCheckedSub<Signed<usize>> for usize

type Output = Signed<usize>

fn opt_checked_sub( self, rhs: Signed<usize>, ) -> Result<Option<Self::Output>, Error>

impl OptionCheckedSub<Duration> for Instant

type Output = Instant

fn opt_checked_sub( self, rhs: Duration, ) -> Result<Option<<Instant as OptionCheckedSub<Duration>>::Output>, Error>

impl OptionCheckedSub<Duration> for SystemTime

type Output = SystemTime

fn opt_checked_sub( self, rhs: Duration, ) -> Result<Option<<SystemTime as OptionCheckedSub<Duration>>::Output>, Error>

impl<T, InnerRhs> OptionCheckedSub<&Option<InnerRhs>, InnerRhs> for Option<T>

where T: OptionOperations + OptionCheckedSub<InnerRhs>, InnerRhs: Copy,

type Output = <T as OptionCheckedSub<InnerRhs>>::Output

fn opt_checked_sub( self, rhs: &Option<InnerRhs>, ) -> Result<Option<<Option<T> as OptionCheckedSub<&Option<InnerRhs>, InnerRhs>>::Output>, Error>

impl<T, InnerRhs> OptionCheckedSub<Option<InnerRhs>, InnerRhs> for Option<T>

where T: OptionOperations + OptionCheckedSub<InnerRhs>,

type Output = <T as OptionCheckedSub<InnerRhs>>::Output

fn opt_checked_sub( self, rhs: Option<InnerRhs>, ) -> Result<Option<<Option<T> as OptionCheckedSub<Option<InnerRhs>, InnerRhs>>::Output>, Error>

impl<T, Rhs> OptionCheckedSub<Rhs> for Option<T>

where T: OptionOperations + OptionCheckedSub<Rhs>,

type Output = <T as OptionCheckedSub<Rhs>>::Output

fn opt_checked_sub( self, rhs: Rhs, ) -> Result<Option<<Option<T> as OptionCheckedSub<Rhs>>::Output>, Error>

Implementors

impl OptionCheckedSub for Signed<u32>

type Output = Signed<u32>

impl OptionCheckedSub for Signed<u64>

type Output = Signed<u64>

impl OptionCheckedSub for Signed<usize>

type Output = Signed<usize>

impl OptionCheckedSub for Signed<Buffers>

type Output = Signed<Buffers>

impl OptionCheckedSub for Signed<Bytes>

type Output = Signed<Bytes>

impl OptionCheckedSub for Signed<ClockTime>

type Output = Signed<ClockTime>

impl OptionCheckedSub for Signed<Default>

type Output = Signed<Default>

impl OptionCheckedSub for Signed<Other>

type Output = Signed<Other>

impl OptionCheckedSub for Signed<Percent>

type Output = Signed<Percent>

impl OptionCheckedSub for Buffers

type Output = Buffers

impl OptionCheckedSub for Bytes

type Output = Bytes

impl OptionCheckedSub for ClockTime

type Output = ClockTime

impl OptionCheckedSub for Default

type Output = Default

impl OptionCheckedSub for Other

type Output = Other

impl OptionCheckedSub for Percent

type Output = Percent

impl OptionCheckedSub<Signed<Buffers>> for Buffers

type Output = Signed<Buffers>

impl OptionCheckedSub<Signed<Bytes>> for Bytes

type Output = Signed<Bytes>

impl OptionCheckedSub<Signed<ClockTime>> for ClockTime

type Output = Signed<ClockTime>

impl OptionCheckedSub<Signed<Default>> for Default

type Output = Signed<Default>

impl OptionCheckedSub<Signed<Other>> for Other

type Output = Signed<Other>

impl OptionCheckedSub<Signed<Percent>> for Percent

type Output = Signed<Percent>

impl OptionCheckedSub<u32> for Signed<u32>

type Output = Signed<u32>

impl OptionCheckedSub<u64> for Signed<u64>

type Output = Signed<u64>

impl OptionCheckedSub<usize> for Signed<usize>

type Output = Signed<usize>

impl OptionCheckedSub<Buffers> for Signed<Buffers>

type Output = Signed<Buffers>

impl OptionCheckedSub<Bytes> for Signed<Bytes>

type Output = Signed<Bytes>

impl OptionCheckedSub<ClockTime> for Signed<ClockTime>

type Output = Signed<ClockTime>

impl OptionCheckedSub<Default> for Signed<Default>

type Output = Signed<Default>

impl OptionCheckedSub<Other> for Signed<Other>

type Output = Signed<Other>

impl OptionCheckedSub<Percent> for Signed<Percent>

type Output = Signed<Percent>

impl<T, InnerRhs> OptionCheckedSub<&Option<InnerRhs>, InnerRhs> for T

where T: OptionOperations + OptionCheckedSub<InnerRhs>, InnerRhs: Copy,

type Output = <T as OptionCheckedSub<InnerRhs>>::Output

impl<T, InnerRhs> OptionCheckedSub<Option<InnerRhs>, InnerRhs> for T

where T: OptionOperations + OptionCheckedSub<InnerRhs>,

type Output = <T as OptionCheckedSub<InnerRhs>>::Output