Struct widestring::ucstr::U16CStr

pub struct U16CStr { /* private fields */ }

C-style 16-bit wide string slice for U16CString.

U16CStr is to U16CString as CStr is to CString.

U16CStr are string slices that do not have a defined encoding. While it is sometimes assumed that they contain possibly invalid or ill-formed UTF-16 data, they may be used for any wide encoded string.

Nul termination

U16CStr is aware of nul (0) values. Unless unchecked conversions are used, all U16CStr strings end with a nul-terminator in the underlying buffer and contain no internal nul values. These strings are intended to be used with C FFI functions that require nul-terminated strings.

Because of the nul termination requirement, multiple classes methods for provided for construction a U16CStr under various scenarios. By default, methods such as from_ptr and from_slice return an error if the input does not terminate with a nul value, or if it contains any interior nul values before the terminator.

_truncate methods on the other hand, such as from_ptr_truncate and from_slice_truncate, construct a slice that terminates with the first nul value encountered in the string, only returning an error if the slice contains no nul values at all. Use this to mimic the behavior of C functions such as strlen when you don’t know if the input is clean of interior nuls.

Finally, unsafe _unchecked variants of these methods, such as from_ptr_unchecked and from_slice_unchecked allow bypassing any checks for nul values, when the input has already been ensured to have a nul terminator and no interior nul values.

Examples

The easiest way to use U16CStr outside of FFI is with the u16cstr! macro to convert string literals into nul-terminated UTF-16 string slices at compile time:

use widestring::u16cstr;
let hello = u16cstr!("Hello, world!");

You can also convert any u16 slice directly, as long as it has a nul terminator:

use widestring::{u16cstr, U16CStr};

let sparkle_heart = [0xd83d, 0xdc96, 0x0];
let sparkle_heart = U16CStr::from_slice(&sparkle_heart).unwrap();

assert_eq!(u16cstr!("💖"), sparkle_heart);

// This unpaired UTf-16 surrogate is invalid UTF-16, but is perfectly valid in U16CStr
let malformed_utf16 = [0xd83d, 0x0];
let s = U16CStr::from_slice(&malformed_utf16).unwrap();

assert_eq!(s.len(), 1);

When working with a FFI, it is useful to create a U16CStr from a pointer:

use widestring::{u16cstr, U16CStr};

let sparkle_heart = [0xd83d, 0xdc96, 0x0];
let s = unsafe {
    // Note the string and pointer length does not include the nul terminator
    U16CStr::from_ptr(sparkle_heart.as_ptr(), sparkle_heart.len() - 1).unwrap()
};
assert_eq!(u16cstr!("💖"), s);

// Alternatively, if the length of the pointer is unknown but definitely terminates in nul,
// a C-style string version can be used
let s = unsafe { U16CStr::from_ptr_str(sparkle_heart.as_ptr()) };

assert_eq!(u16cstr!("💖"), s);

Implementations

impl U16CStr

pub const NUL_TERMINATOR: u16 = 0u16

The nul terminator character value.

pub fn new<S: AsRef<U16CStr> + ?Sized>(s: &S) -> &Self

Coerces a value into a wide C string slice.

pub unsafe fn from_ptr_str<'a>(p: *const u16) -> &'a Self

Constructs a wide C string slice from a nul-terminated string pointer.

This will scan for nul values beginning with p. The first nul value will be used as the nul terminator for the string, similar to how libc string functions such as strlen work.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid or has a nul terminator, and the function could scan past the underlying buffer.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts. In particular, the returned string reference must not be mutated for the duration of lifetime 'a, except inside an UnsafeCell.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr_str_mut<'a>(p: *mut u16) -> &'a mut Self

Constructs a mutable wide C string slice from a mutable nul-terminated string pointer.

This will scan for nul values beginning with p. The first nul value will be used as the nul terminator for the string, similar to how libc string functions such as strlen work.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid or has a nul terminator, and the function could scan past the underlying buffer.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts_mut.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr<'a>( p: *const u16, len: usize ) -> Result<&'a Self, NulError<u16>>

Constructs a wide C string slice from a pointer and a length.

The len argument is the number of elements, not the number of bytes, and does not include the nul terminator of the string. Thus, a len of 0 is valid and means that p is a pointer directly to the nul terminator of the string.

Errors

This will scan the pointer string for an interior nul value and error if one is found before the nul terminator at len offset. To avoid scanning for interior nuls, from_ptr_unchecked may be used instead.

An error is returned if the value at len offset is not a nul terminator.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid for len + 1 elements.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts. In particular, the returned string reference must not be mutated for the duration of lifetime 'a, except inside an UnsafeCell.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr_mut<'a>( p: *mut u16, len: usize ) -> Result<&'a mut Self, NulError<u16>>

Constructs a mutable wide C string slice from a mutable pointer and a length.

The len argument is the number of elements, not the number of bytes, and does not include the nul terminator of the string. Thus, a len of 0 is valid and means that p is a pointer directly to the nul terminator of the string.

Errors

This will scan the pointer string for an interior nul value and error if one is found before the nul terminator at len offset. To avoid scanning for interior nuls, from_ptr_unchecked_mut may be used instead.

An error is returned if the value at len offset is not a nul terminator.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid for len + 1 elements.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts_mut.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr_truncate<'a>( p: *const u16, len: usize ) -> Result<&'a Self, MissingNulTerminator>

Constructs a wide C string slice from a pointer and a length, truncating at the first nul terminator.

The len argument is the number of elements, not the number of bytes. This will scan for nul values beginning with p until offset len. The first nul value will be used as the nul terminator for the string, ignoring any remaining values left before len.

Errors

If no nul terminator is found after len + 1 elements, an error is returned.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid or has a nul terminator, and the function could scan past the underlying buffer.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts. In particular, the returned string reference must not be mutated for the duration of lifetime 'a, except inside an UnsafeCell.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for thev string, or by explicit annotation.

pub unsafe fn from_ptr_truncate_mut<'a>( p: *mut u16, len: usize ) -> Result<&'a mut Self, MissingNulTerminator>

Constructs a mutable wide C string slice from a mutable pointer and a length, truncating at the first nul terminator.

The len argument is the number of elements, not the number of bytes. This will scan for nul values beginning with p until offset len. The first nul value will be used as the nul terminator for the string, ignoring any remaining values left before len.

Errors

If no nul terminator is found after len + 1 elements, an error is returned.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid or has a nul terminator, and the function could scan past the underlying buffer.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts_mut.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr_unchecked<'a>(p: *const u16, len: usize) -> &'a Self

Constructs a wide C string slice from a pointer and a length without checking for any nul values.

The len argument is the number of elements, not the number of bytes, and does not include the nul terminator of the string. Thus, a len of 0 is valid and means that p is a pointer directly to the nul terminator of the string.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid for len + 1 elements, nor that it has a terminating nul value.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts. In particular, the returned string reference must not be mutated for the duration of lifetime 'a, except inside an UnsafeCell.

The interior values of the pointer are not scanned for nul. Any interior nul values or a missing nul terminator at pointer offset len + 1 will result in an invalid string slice.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub unsafe fn from_ptr_unchecked_mut<'a>( p: *mut u16, len: usize ) -> &'a mut Self

Constructs a mutable wide C string slice from a mutable pointer and a length without checking for any nul values.

The len argument is the number of elements, not the number of bytes, and does not include the nul terminator of the string. Thus, a len of 0 is valid and means that p is a pointer directly to the nul terminator of the string.

Safety

This function is unsafe as there is no guarantee that the given pointer is valid for len + 1 elements, nor that is has a terminating nul value.

In addition, the data must meet the safety conditions of std::slice::from_raw_parts_mut.

The interior values of the pointer are not scanned for nul. Any interior nul values or a missing nul terminator at pointer offset len + 1 will result in an invalid string slice.

Panics

This function panics if p is null.

Caveat

The lifetime for the returned string is inferred from its usage. To prevent accidental misuse, it’s suggested to tie the lifetime to whichever source lifetime is safe in the context, such as by providing a helper function taking the lifetime of a host value for the string, or by explicit annotation.

pub fn from_slice(slice: &[u16]) -> Result<&Self, NulError<u16>>

Constructs a wide C string slice from a slice of values with a terminating nul, checking for invalid interior nul values.

The slice must have at least one item, the nul terminator, even for an empty string.

Errors

If there are nul values in the slice except for the last value, an error is returned.

An error is also returned if the last value of the slice is not a nul terminator.

pub fn from_slice_mut(slice: &mut [u16]) -> Result<&mut Self, NulError<u16>>

Constructs a mutable wide C string slice from a mutable slice of values with a terminating nul, checking for invalid interior nul values.

The slice must have at least one item, the nul terminator, even for an empty string.

Errors

If there are nul values in the slice except for the last value, an error is returned.

An error is also returned if the last value of the slice is not a nul terminator.

pub fn from_slice_truncate(slice: &[u16]) -> Result<&Self, MissingNulTerminator>

Constructs a wide C string slice from a slice of values, truncating at the first nul terminator.

The slice will be scanned for nul values. When a nul value is found, it is treated as the terminator for the string, and the string slice will be truncated to that nul.

Errors

If there are no nul values in the slice, an error is returned.

pub fn from_slice_truncate_mut( slice: &mut [u16] ) -> Result<&mut Self, MissingNulTerminator>

Constructs a mutable wide C string slice from a mutable slice of values, truncating at the first nul terminator.

The slice will be scanned for nul values. When a nul value is found, it is treated as the terminator for the string, and the string slice will be truncated to that nul.

Errors

If there are no nul values in the slice, an error is returned.

pub const unsafe fn from_slice_unchecked(slice: &[u16]) -> &Self

Constructs a wide C string slice from a slice of values without checking for a terminating or interior nul values.

Safety

This function is unsafe because it can lead to invalid string slice values when the slice is missing a terminating nul value or there are non-terminating interior nul values in the slice. In particular, an empty slice will result in an invalid string slice.

pub unsafe fn from_slice_unchecked_mut(slice: &mut [u16]) -> &mut Self

Constructs a mutable wide C string slice from a mutable slice of values without checking for a terminating or interior nul values.

Safety

This function is unsafe because it can lead to invalid string slice values when the slice is missing a terminating nul value or there are non-terminating interior nul values in the slice. In particular, an empty slice will result in an invalid string slice.

pub fn to_ucstring(&self) -> U16CString

Available on crate feature alloc only.

Copies the string reference to a new owned wide C string.

pub fn to_ustring(&self) -> U16String

Available on crate feature alloc only.

Copies the string reference to a new owned wide string.

The resulting wide string will not have a nul terminator.

Examples

use widestring::U16CString;
let wcstr = U16CString::from_str("MyString").unwrap();
// Convert U16CString to a U16String
let wstr = wcstr.to_ustring();

// U16CString will have a terminating nul
let wcvec = wcstr.into_vec_with_nul();
assert_eq!(wcvec[wcvec.len()-1], 0);
// The resulting U16String will not have the terminating nul
let wvec = wstr.into_vec();
assert_ne!(wvec[wvec.len()-1], 0);

pub fn as_slice(&self) -> &[u16]

Converts to a slice of the underlying elements.

The slice will not include the nul terminator.

pub unsafe fn as_mut_slice(&mut self) -> &mut [u16]

Converts to a mutable slice of the underlying elements.

The slice will not include the nul terminator.

Safety

This method is unsafe because you can violate the invariants of this type when mutating the slice (i.e. by adding interior nul values).

pub const fn as_slice_with_nul(&self) -> &[u16]

Converts to a slice of the underlying elements, including the nul terminator.

pub const fn as_ptr(&self) -> *const u16

Returns a raw pointer to the string.

The caller must ensure that the string outlives the pointer this function returns, or else it will end up pointing to garbage.

The caller must also ensure that the memory the pointer (non-transitively) points to is never written to (except inside an UnsafeCell) using this pointer or any pointer derived from it. If you need to mutate the contents of the string, use as_mut_ptr.

Modifying the container referenced by this string may cause its buffer to be reallocated, which would also make any pointers to it invalid.

pub fn as_mut_ptr(&mut self) -> *mut u16

Returns a mutable raw pointer to the string.

The caller must ensure that the string outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the container referenced by this string may cause its buffer to be reallocated, which would also make any pointers to it invalid.

pub fn as_ptr_range(&self) -> Range<*const u16>

Returns the two raw pointers spanning the string slice.

The returned range is half-open, which means that the end pointer points one past the last element of the slice. This way, an empty slice is represented by two equal pointers, and the difference between the two pointers represents the size of the slice.

See as_ptr for warnings on using these pointers. The end pointer requires extra caution, as it does not point to a valid element in the slice.

This function is useful for interacting with foreign interfaces which use two pointers to refer to a range of elements in memory, as is common in C++.

pub fn as_mut_ptr_range(&mut self) -> Range<*mut u16>

Returns the two unsafe mutable pointers spanning the string slice.

The returned range is half-open, which means that the end pointer points one past the last element of the slice. This way, an empty slice is represented by two equal pointers, and the difference between the two pointers represents the size of the slice.

See as_mut_ptr for warnings on using these pointers. The end pointer requires extra caution, as it does not point to a valid element in the slice.

This function is useful for interacting with foreign interfaces which use two pointers to refer to a range of elements in memory, as is common in C++.

pub const fn len(&self) -> usize

Returns the length of the string as number of elements (not number of bytes) not including nul terminator.

pub const fn is_empty(&self) -> bool

Returns whether this string contains no data (i.e. is only the nul terminator).

pub fn into_ucstring(self: Box<Self>) -> U16CString

Available on crate feature alloc only.

Converts a boxed wide C string slice into an wide C string without copying or allocating.

Examples

use widestring::U16CString;

let v = vec![102u16, 111u16, 111u16]; // "foo"
let c_string = U16CString::from_vec(v.clone()).unwrap();
let boxed = c_string.into_boxed_ucstr();
assert_eq!(boxed.into_ucstring(), U16CString::from_vec(v).unwrap());

pub fn as_ustr(&self) -> &U16Str

Returns a wide string slice to this wide C string slice.

The wide string slice will not include the nul-terminator.

pub fn as_ustr_with_nul(&self) -> &U16Str

Returns a wide string slice to this wide C string slice.

The wide string slice will include the nul-terminator.

pub unsafe fn as_mut_ustr(&mut self) -> &mut U16Str

Returns a mutable wide string slice to this wide C string slice.

The wide string slice will not include the nul-terminator.

Safety

This method is unsafe because you can violate the invariants of this type when mutating the string (i.e. by adding interior nul values).

pub fn display(&self) -> Display<'_, U16CStr>

Returns an object that implements Display for printing strings that may contain non-Unicode data.

A wide C string might data of any encoding. This function assumes the string is encoded in UTF-16, and returns a struct implements the Display trait in a way that decoding the string is lossy but no heap allocations are performed, such as by to_string_lossy.

By default, invalid Unicode data is replaced with U+FFFD REPLACEMENT CHARACTER (�). If you wish to simply skip any invalid Uncode data and forego the replacement, you may use the alternate formatting with {:#}.

Examples

Basic usage:

use widestring::U16CStr;

// 𝄞mus<invalid>ic<invalid>
let s = U16CStr::from_slice(&[
    0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0xDD1E, 0x0069, 0x0063, 0xD834, 0x0000,
]).unwrap();

assert_eq!(format!("{}", s.display()),
"𝄞mus�ic�"
);

Using alternate formatting style to skip invalid values entirely:

use widestring::U16CStr;

// 𝄞mus<invalid>ic<invalid>
let s = U16CStr::from_slice(&[
    0xD834, 0xDD1E, 0x006d, 0x0075, 0x0073, 0xDD1E, 0x0069, 0x0063, 0xD834, 0x0000,
]).unwrap();

assert_eq!(format!("{:#}", s.display()),
"𝄞music"
);

pub fn get<I>(&self, i: I) -> Option<&U16Str>

where I: SliceIndex<[u16], Output = [u16]>,

Returns a subslice of the string.

This is the non-panicking alternative to indexing the string. Returns None whenever equivalent indexing operation would panic.

pub unsafe fn get_mut<I>(&mut self, i: I) -> Option<&mut U16Str>

where I: SliceIndex<[u16], Output = [u16]>,

Returns a mutable subslice of the string.

This is the non-panicking alternative to indexing the string. Returns None whenever equivalent indexing operation would panic.

Safety

This method is unsafe because you can violate the invariants of this type when mutating the memory the pointer points to (i.e. by adding interior nul values).

pub unsafe fn get_unchecked<I>(&self, i: I) -> &U16Str

where I: SliceIndex<[u16], Output = [u16]>,

Returns an unchecked subslice of the string.

This is the unchecked alternative to indexing the string.

Safety

Callers of this function are responsible that these preconditions are satisfied:

• The starting index must not exceed the ending index;
• Indexes must be within bounds of the original slice.

Failing that, the returned string slice may reference invalid memory.

pub unsafe fn get_unchecked_mut<I>(&mut self, i: I) -> &mut U16Str

where I: SliceIndex<[u16], Output = [u16]>,

Returns aa mutable, unchecked subslice of the string.

This is the unchecked alternative to indexing the string.

Safety

Callers of this function are responsible that these preconditions are satisfied:

• The starting index must not exceed the ending index;
• Indexes must be within bounds of the original slice.

Failing that, the returned string slice may reference invalid memory.

This method is unsafe because you can violate the invariants of this type when mutating the memory the pointer points to (i.e. by adding interior nul values).

pub fn split_at(&self, mid: usize) -> (&U16Str, &U16Str)

Divide one string slice into two at an index.

The argument, mid, should be an offset from the start of the string.

The two slices returned go from the start of the string slice to mid, and from mid to the end of the string slice.

To get mutable string slices instead, see the split_at_mut method.

pub unsafe fn split_at_mut(&mut self, mid: usize) -> (&mut U16Str, &mut U16Str)

Divide one mutable string slice into two at an index.

The argument, mid, should be an offset from the start of the string.

The two slices returned go from the start of the string slice to mid, and from mid to the end of the string slice.

To get immutable string slices instead, see the split_at method.

Safety

This method is unsafe because you can violate the invariants of this type when mutating the memory the pointer points to (i.e. by adding interior nul values).

pub fn repeat(&self, n: usize) -> U16CString

Available on crate feature alloc only.

Creates a new owned string by repeating this string n times.

Panics

This function will panic if the capacity would overflow.

impl U16CStr

pub fn to_os_string(&self) -> OsString

Available on crate feature std only.

Copys a string to an owned OsString.

This makes a string copy of the U16CStr. Since U16CStr makes no guarantees that it is valid UTF-16, there is no guarantee that the resulting OsString will be valid data. The OsString will not have a nul terminator.

Note that the encoding of OsString is platform-dependent, so on some platforms this may make an encoding conversions, while on other platforms (such as windows) no changes to the string will be made.

Examples

use widestring::U16CString;
use std::ffi::OsString;
let s = "MyString";
// Create a wide string from the string
let wstr = U16CString::from_str(s).unwrap();
// Create an OsString from the wide string
let osstr = wstr.to_os_string();

assert_eq!(osstr, OsString::from(s));

pub fn to_string(&self) -> Result<String, Utf16Error>

Available on crate feature alloc only.

Copies the string to a String if it contains valid UTF-16 data.

This method assumes this string is encoded as UTF-16 and attempts to decode it as such. It will *not have a nul terminator.

Errors

Returns an error if the string contains any invalid UTF-16 data.

Examples

use widestring::U16CString;
let s = "MyString";
// Create a wide string from the string
let wstr = U16CString::from_str(s).unwrap();
// Create a regular string from the wide string
let s2 = wstr.to_string().unwrap();

assert_eq!(s2, s);

pub fn to_string_lossy(&self) -> String

Available on crate feature alloc only.

Decodes the string reference to a String even if it is invalid UTF-16 data.

This method assumes this string is encoded as UTF-16 and attempts to decode it as such. Any invalid sequences are replaced with U+FFFD REPLACEMENT CHARACTER, which looks like this: �. It will *not have a nul terminator.

Examples

use widestring::U16CString;
let s = "MyString";
// Create a wide string from the string
let wstr = U16CString::from_str(s).unwrap();
// Create a regular string from the wide string
let s2 = wstr.to_string_lossy();

assert_eq!(s2, s);

pub fn chars(&self) -> CharsUtf16<'_>

Returns an iterator over the chars of a string slice.

As this string has no defined encoding, this method assumes the string is UTF-16. Since it may consist of invalid UTF-16, the iterator returned by this method is an iterator over Result<char, DecodeUtf16Error> instead of chars directly. If you would like a lossy iterator over charss directly, instead use chars_lossy.

It’s important to remember that char represents a Unicode Scalar Value, and may not match your idea of what a ‘character’ is. Iteration over grapheme clusters may be what you actually want. That functionality is not provided by by this crate.

pub fn chars_lossy(&self) -> CharsLossyUtf16<'_>

Returns a lossy iterator over the chars of a string slice.

As this string has no defined encoding, this method assumes the string is UTF-16. Since it may consist of invalid UTF-16, the iterator returned by this method will replace unpaired surrogates with U+FFFD REPLACEMENT CHARACTER (�). This is a lossy version of chars.

It’s important to remember that char represents a Unicode Scalar Value, and may not match your idea of what a ‘character’ is. Iteration over grapheme clusters may be what you actually want. That functionality is not provided by by this crate.

pub fn char_indices(&self) -> CharIndicesUtf16<'_>

Returns an iterator over the chars of a string slice, and their positions.

As this string has no defined encoding, this method assumes the string is UTF-16. Since it may consist of invalid UTF-16, the iterator returned by this method is an iterator over is an iterator over Result<char, DecodeUtf16Error> as well as their positions, instead of chars directly. If you would like a lossy indices iterator over charss directly, instead use char_indices_lossy.

The iterator yields tuples. The position is first, the char is second.

pub fn char_indices_lossy(&self) -> CharIndicesLossyUtf16<'_>

Returns a lossy iterator over the chars of a string slice, and their positions.

As this string slice may consist of invalid UTF-16, the iterator returned by this method will replace unpaired surrogates with U+FFFD REPLACEMENT CHARACTER (�), as well as the positions of all characters. This is a lossy version of char_indices.

The iterator yields tuples. The position is first, the char is second.

Trait Implementations

impl Add<&U16CStr> for U16String

Available on crate feature alloc only.

type Output = U16String

The resulting type after applying the + operator.

fn add(self, rhs: &U16CStr) -> Self::Output

Performs the + operation.

impl AddAssign<&U16CStr> for U16String

Available on crate feature alloc only.

fn add_assign(&mut self, rhs: &U16CStr)

Performs the += operation.

impl AsMut<U16CStr> for U16CStr

fn as_mut(&mut self) -> &mut U16CStr

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsMut<U16CStr> for U16CString

Available on crate feature alloc only.

fn as_mut(&mut self) -> &mut U16CStr

Converts this type into a mutable reference of the (usually inferred) input type.

impl AsRef<[u16]> for U16CStr

fn as_ref(&self) -> &[u16]

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<U16CStr> for U16CStr

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<U16CStr> for U16CString

Available on crate feature alloc only.

fn as_ref(&self) -> &U16CStr

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<U16Str> for U16CStr

fn as_ref(&self) -> &U16Str

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<U16CStr> for U16CString

Available on crate feature alloc only.

fn borrow(&self) -> &U16CStr

Immutably borrows from an owned value.

impl BorrowMut<U16CStr> for U16CString

Available on crate feature alloc only.

fn borrow_mut(&mut self) -> &mut U16CStr

Mutably borrows from an owned value.

impl Debug for U16CStr

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

Formats the value using the given formatter.

impl<'a> Default for &'a U16CStr

fn default() -> Self

Returns the “default value” for a type.

impl Default for Box<U16CStr>

fn default() -> Box<U16CStr>

Returns the “default value” for a type.

impl<'a> Extend<&'a U16CStr> for U16String

Available on crate feature alloc only.

fn extend<T: IntoIterator<Item = &'a U16CStr>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl<'a> From<&'a U16CStr> for Box<U16CStr>

fn from(s: &'a U16CStr) -> Box<U16CStr>

Converts to this type from the input type.

impl<'a> From<&'a U16CStr> for Cow<'a, U16CStr>

Available on crate feature alloc only.

fn from(s: &'a U16CStr) -> Cow<'a, U16CStr>

Converts to this type from the input type.

impl From<&U16CStr> for OsString

fn from(s: &U16CStr) -> OsString

Converts to this type from the input type.

impl From<U16CString> for Box<U16CStr>

Available on crate feature alloc only.

fn from(s: U16CString) -> Box<U16CStr>

Converts to this type from the input type.

impl<'a> FromIterator<&'a U16CStr> for U16String

Available on crate feature alloc only.

fn from_iter<T: IntoIterator<Item = &'a U16CStr>>(iter: T) -> Self

Creates a value from an iterator.

impl Hash for U16CStr

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

impl<I> Index<I> for U16CStr

where I: SliceIndex<[u16], Output = [u16]>,

type Output = U16Str

The returned type after indexing.

fn index(&self, index: I) -> &Self::Output

Performs the indexing (container[index]) operation.

impl Ord for U16CStr

fn cmp(&self, other: &U16CStr) -> Ordering

This method returns an Ordering between self and other.

impl PartialEq<&U16CStr> for U16CStr

fn eq(&self, other: &&U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> PartialEq<&'a U16CStr> for U16CString

Available on crate feature alloc only.

fn eq(&self, other: &&'a U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<&U16CStr> for U16Str

fn eq(&self, other: &&U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> PartialEq<&'a U16CStr> for U16String

Available on crate feature alloc only.

fn eq(&self, other: &&'a U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<&U16Str> for U16CStr

fn eq(&self, other: &&U16Str) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for &U16CStr

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for &U16Str

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for U16CString

Available on crate feature alloc only.

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for U16Str

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for U16String

Available on crate feature alloc only.

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for Utf16Str

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CStr> for Utf16String

Available on crate feature alloc only.

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CString> for &U16CStr

Available on crate feature alloc only.

fn eq(&self, other: &U16CString) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16CString> for U16CStr

Available on crate feature alloc only.

fn eq(&self, other: &U16CString) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16Str> for &U16CStr

fn eq(&self, other: &U16Str) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16Str> for U16CStr

fn eq(&self, other: &U16Str) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16String> for &U16CStr

Available on crate feature alloc only.

fn eq(&self, other: &U16String) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<U16String> for U16CStr

Available on crate feature alloc only.

fn eq(&self, other: &U16String) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<Utf16Str> for U16CStr

fn eq(&self, other: &Utf16Str) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<Utf16String> for U16CStr

Available on crate feature alloc only.

fn eq(&self, other: &Utf16String) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for U16CStr

fn eq(&self, other: &U16CStr) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a> PartialOrd<&'a U16CStr> for U16CString

Available on crate feature alloc only.

fn partial_cmp(&self, other: &&'a U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> PartialOrd<&'a U16CStr> for U16String

Available on crate feature alloc only.

fn partial_cmp(&self, other: &&'a U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<U16CStr> for U16CString

Available on crate feature alloc only.

fn partial_cmp(&self, other: &U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<U16CStr> for U16Str

fn partial_cmp(&self, other: &U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<U16CStr> for U16String

Available on crate feature alloc only.

fn partial_cmp(&self, other: &U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd<U16Str> for U16CStr

fn partial_cmp(&self, other: &U16Str) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd for U16CStr

fn partial_cmp(&self, other: &U16CStr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl ToOwned for U16CStr

Available on crate feature alloc only.

type Owned = U16CString

The resulting type after obtaining ownership.

fn to_owned(&self) -> U16CString

Creates owned data from borrowed data, usually by cloning.

fn clone_into(&self, target: &mut Self::Owned)

Uses borrowed data to replace owned data, usually by cloning.

impl<'a> TryFrom<&'a U16CStr> for &'a Utf16Str

type Error = Utf16Error

The type returned in the event of a conversion error.

fn try_from(value: &'a U16CStr) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<&U16CStr> for Utf16String

Available on crate feature alloc only.

type Error = Utf16Error

The type returned in the event of a conversion error.

fn try_from(value: &U16CStr) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for U16CStr

impl StructuralPartialEq for U16CStr