alloc::ffi::c_str

# Struct NulError

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    pub struct NulError(/* private fields */);

🔬This is a nightly-only experimental API. (`c_str_module` #112134)
Expand description

An error indicating that an interior nul byte was found.

While Rust strings may contain nul bytes in the middle, C strings can’t, as that byte would effectively truncate the string.

This error is created by the `new` method on `CString`. See its documentation for more.

## §Examples

    use std::ffi::{CString, NulError};

    let _: NulError = CString::new(b"f\0oo".to_vec()).unwrap_err();

## Implementations§

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### impl NulError

1.0.0 · Source

#### pub fn nul_position(&self) -> usize

Returns the position of the nul byte in the slice that caused `CString::new` to fail.

##### §Examples

    use std::ffi::CString;

    let nul_error = CString::new("foo\0bar").unwrap_err();
    assert_eq!(nul_error.nul_position(), 3);

    let nul_error = CString::new("foo bar\0").unwrap_err();
    assert_eq!(nul_error.nul_position(), 7);

1.0.0 · Source

#### pub fn into_vec(self) -> Vec<u8>

Consumes this error, returning the underlying vector of bytes which generated the error in the first place.

##### §Examples

    use std::ffi::CString;

    let nul_error = CString::new("foo\0bar").unwrap_err();
    assert_eq!(nul_error.into_vec(), b"foo\0bar");

## Trait Implementations§

1.64.0 · Source§

### impl Clone for NulError

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#### fn clone(&self) -> NulError

Returns a copy of the value. Read more
1.0.0 · Source§

#### fn clone_from(&mut self, source: &Self)

Performs copy-assignment from `source`. Read more
1.64.0 · Source§

### impl Debug for NulError

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#### fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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### impl Display for NulError

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#### fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
1.0.0 · Source§

### impl Error for NulError

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#### fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()
Read more
1.30.0 · Source§

#### fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any. Read more
1.0.0 · Source§

#### fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
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#### fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (`error_generic_member_access` #99301)
Provides type-based access to context intended for error reports. Read more
1.64.0 · Source§

### impl PartialEq for NulError

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#### fn eq(&self, other: &NulError) -> bool

Tests for `self` and `other` values to be equal, and is used by `==`.
1.0.0 · Source§

#### fn ne(&self, other: &Rhs) -> bool

Tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
1.64.0 · Source§

### impl Eq for NulError

1.64.0 · Source§

### impl StructuralPartialEq for NulError

## Auto Trait Implementations§

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### impl Freeze for NulError

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### impl RefUnwindSafe for NulError

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### impl Send for NulError

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### impl Sync for NulError

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### impl Unpin for NulError

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### impl UnwindSafe for NulError

## Blanket Implementations§

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### impl<T> Any for T
where T: 'static + ?Sized,

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#### fn type_id(&self) -> TypeId

Gets the `TypeId` of `self`. Read more
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### impl<T> Borrow<T> for T
where T: ?Sized,

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#### fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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### impl<T> BorrowMut<T> for T
where T: ?Sized,

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#### fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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### impl<T> CloneToUninit for T
where T: Clone,

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#### unsafe fn clone_to_uninit(&self, dst: *mut u8)

🔬This is a nightly-only experimental API. (`clone_to_uninit` #126799)
Performs copy-assignment from `self` to `dst`. Read more
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### impl<T> From<T> for T

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#### fn from(t: T) -> T

Returns the argument unchanged.

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### impl<T, U> Into<U> for T
where U: From<T>,

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#### fn into(self) -> U

Calls `U::from(self)`.

That is, this conversion is whatever the implementation of `From<T> for U` chooses to do.

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### impl<T> ToOwned for T
where T: Clone,

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#### type Owned = T

The resulting type after obtaining ownership.
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#### fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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#### fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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### impl<T> ToString for T
where T: Display + ?Sized,

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#### default fn to_string(&self) -> String

Converts the given value to a `String`. Read more
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### impl<T, U> TryFrom<U> for T
where U: Into<T>,

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#### type Error = Infallible

The type returned in the event of a conversion error.
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#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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### impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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#### type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.