Trait CheckBytes 

pub unsafe trait CheckBytes<C: Fallible + ?Sized> {
    // Required method
    unsafe fn check_bytes(
        value: *const Self,
        context: &mut C,
    ) -> Result<(), C::Error>;
}

A type that can check whether a pointer points to a valid value.

CheckBytes can be derived with CheckBytes or implemented manually for custom behavior.

Safety

check_bytes must only return Ok if value points to a valid instance of Self. Because value must always be properly aligned for Self and point to enough bytes to represent the type, this implies that value may be dereferenced safely.

Example

use core::{error::Error, fmt};

use bytecheck::CheckBytes;
use rancor::{fail, Fallible, Source};

#[repr(C, align(4))]
pub struct NonMaxU32(u32);

unsafe impl<C: Fallible + ?Sized> CheckBytes<C> for NonMaxU32
where
    C::Error: Source,
{
    unsafe fn check_bytes(
        value: *const Self,
        context: &mut C,
    ) -> Result<(), C::Error> {
        #[derive(Debug)]
        struct NonMaxCheckError;

        impl fmt::Display for NonMaxCheckError {
            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                write!(f, "non-max u32 was set to u32::MAX")
            }
        }

        impl Error for NonMaxCheckError {}

        let value = unsafe { value.read() };
        if value.0 == u32::MAX {
            fail!(NonMaxCheckError);
        }

        Ok(())
    }
}

See Verify for an example which uses less unsafe.

Required Methods

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

Checks whether the given pointer points to a valid value within the given context.

Safety

The passed pointer must be aligned and point to enough initialized bytes to represent the type.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<C> CheckBytes<C> for bool

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for char

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(ptr: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for str

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for CStr

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroI8

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroI16

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroI32

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroI64

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroI128

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroU8

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroU16

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroU32

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroU64

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for NonZeroU128

where C: Fallible + ?Sized, C::Error: Source,

unsafe fn check_bytes(value: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C> CheckBytes<C> for AtomicBool

where C: Fallible + ?Sized, C::Error: Source,

Available on target_has_atomic=8 only.

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for f32

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for f64

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for i8

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for i16

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for i32

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for i64

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for i128

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for u8

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for u16

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for u32

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for u64

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for u128

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for ()

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for PhantomPinned

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for RangeFull

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicI8

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicI16

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicI32

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicI64

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicU8

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicU16

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicU32

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<C: Fallible + ?Sized> CheckBytes<C> for AtomicU64

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

impl<T0, C> CheckBytes<C> for (T0,)

where T0: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, C> CheckBytes<C> for (T0, T1)

where T0: CheckBytes<C>, T1: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, C> CheckBytes<C> for (T0, T1, T2)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, C> CheckBytes<C> for (T0, T1, T2, T3)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, C> CheckBytes<C> for (T0, T1, T2, T3, T4)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7, T8)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, T8: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, T8: CheckBytes<C>, T9: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, T8: CheckBytes<C>, T9: CheckBytes<C>, T10: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, T8: CheckBytes<C>, T9: CheckBytes<C>, T10: CheckBytes<C>, T11: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, C> CheckBytes<C> for (T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12)

where T0: CheckBytes<C>, T1: CheckBytes<C>, T2: CheckBytes<C>, T3: CheckBytes<C>, T4: CheckBytes<C>, T5: CheckBytes<C>, T6: CheckBytes<C>, T7: CheckBytes<C>, T8: CheckBytes<C>, T9: CheckBytes<C>, T10: CheckBytes<C>, T11: CheckBytes<C>, T12: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for [T]

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for Cell<T>

where T: CheckBytes<C> + ?Sized, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes(value: *const Self, c: &mut C) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for UnsafeCell<T>

where T: CheckBytes<C> + ?Sized, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes(value: *const Self, c: &mut C) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for ManuallyDrop<T>

where T: CheckBytes<C> + ?Sized, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes(value: *const Self, c: &mut C) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for Range<T>

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for RangeFrom<T>

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for RangeTo<T>

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, C> CheckBytes<C> for RangeToInclusive<T>

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T, const N: usize, C> CheckBytes<C> for [T; N]

where T: CheckBytes<C>, C: Fallible + ?Sized, C::Error: Trace,

unsafe fn check_bytes( value: *const Self, context: &mut C, ) -> Result<(), C::Error>

impl<T: ?Sized, C: Fallible + ?Sized> CheckBytes<C> for PhantomData<T>

unsafe fn check_bytes(_: *const Self, _: &mut C) -> Result<(), C::Error>

Implementors