Struct sexually_transmitted_disease::ffi::OsString 1.0.0[−][src]
pub struct OsString { /* fields omitted */ }
Expand description
A type that can represent owned, mutable platform-native strings, but is cheaply inter-convertible with Rust strings.
The need for this type arises from the fact that:
-
On Unix systems, strings are often arbitrary sequences of non-zero bytes, in many cases interpreted as UTF-8.
-
On Windows, strings are often arbitrary sequences of non-zero 16-bit values, interpreted as UTF-16 when it is valid to do so.
-
In Rust, strings are always valid UTF-8, which may contain zeros.
OsString
and OsStr
bridge this gap by simultaneously representing Rust
and platform-native string values, and in particular allowing a Rust string
to be converted into an “OS” string with no cost if possible. A consequence
of this is that OsString
instances are not NUL
terminated; in order
to pass to e.g., Unix system call, you should create a CStr
.
OsString
is to &OsStr
as String
is to &str
: the former
in each pair are owned strings; the latter are borrowed
references.
Note, OsString
and OsStr
internally do not necessarily hold strings in
the form native to the platform; While on Unix, strings are stored as a
sequence of 8-bit values, on Windows, where strings are 16-bit value based
as just discussed, strings are also actually stored as a sequence of 8-bit
values, encoded in a less-strict variant of UTF-8. This is useful to
understand when handling capacity and length values.
Creating an OsString
From a Rust string: OsString
implements
From<String>
, so you can use my_string.into()
to
create an OsString
from a normal Rust string.
From slices: Just like you can start with an empty Rust
String
and then String::push_str
some &str
sub-string slices into it, you can create an empty OsString
with
the OsString::new
method and then push string slices into it with the
OsString::push
method.
Extracting a borrowed reference to the whole OS string
You can use the OsString::as_os_str
method to get an &OsStr
from
an OsString
; this is effectively a borrowed reference to the
whole string.
Conversions
See the module’s toplevel documentation about conversions for a discussion on
the traits which OsString
implements for conversions from/to native representations.
Implementations
Creates a new OsString
with the given capacity.
The string will be able to hold exactly capacity
length units of other
OS strings without reallocating. If capacity
is 0, the string will not
allocate.
See main OsString
documentation information about encoding.
Examples
use std::ffi::OsString;
let mut os_string = OsString::with_capacity(10);
let capacity = os_string.capacity();
// This push is done without reallocating
os_string.push("foo");
assert_eq!(capacity, os_string.capacity());
Truncates the OsString
to zero length.
Examples
use std::ffi::OsString;
let mut os_string = OsString::from("foo");
assert_eq!(&os_string, "foo");
os_string.clear();
assert_eq!(&os_string, "");
Returns the capacity this OsString
can hold without reallocating.
See OsString
introduction for information about encoding.
Examples
use std::ffi::OsString;
let os_string = OsString::with_capacity(10);
assert!(os_string.capacity() >= 10);
Reserves capacity for at least additional
more capacity to be inserted
in the given OsString
.
The collection may reserve more space to avoid frequent reallocations.
Examples
use std::ffi::OsString;
let mut s = OsString::new();
s.reserve(10);
assert!(s.capacity() >= 10);
Reserves the minimum capacity for exactly additional
more capacity to
be inserted in the given OsString
. Does nothing if the capacity is
already sufficient.
Note that the allocator may give the collection more space than it
requests. Therefore, capacity can not be relied upon to be precisely
minimal. Prefer reserve
if future insertions are expected.
Examples
use std::ffi::OsString;
let mut s = OsString::new();
s.reserve_exact(10);
assert!(s.capacity() >= 10);
Shrinks the capacity of the OsString
to match its length.
Examples
use std::ffi::OsString;
let mut s = OsString::from("foo");
s.reserve(100);
assert!(s.capacity() >= 100);
s.shrink_to_fit();
assert_eq!(3, s.capacity());
Shrinks the capacity of the OsString
with a lower bound.
The capacity will remain at least as large as both the length and the supplied value.
If the current capacity is less than the lower limit, this is a no-op.
Examples
use std::ffi::OsString;
let mut s = OsString::from("foo");
s.reserve(100);
assert!(s.capacity() >= 100);
s.shrink_to(10);
assert!(s.capacity() >= 10);
s.shrink_to(0);
assert!(s.capacity() >= 3);
1.20.0[src]pub fn into_boxed_os_str(self) -> Box<OsStr, Global>ⓘimpl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
pub fn into_boxed_os_str(self) -> Box<OsStr, Global>ⓘimpl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
Methods from Deref<Target = OsStr>
Converts an OsStr
to a Cow<str>
.
Any non-Unicode sequences are replaced with
U+FFFD REPLACEMENT CHARACTER
.
Examples
Calling to_string_lossy
on an OsStr
with invalid unicode:
// Note, due to differences in how Unix and Windows represent strings,
// we are forced to complicate this example, setting up example `OsStr`s
// with different source data and via different platform extensions.
// Understand that in reality you could end up with such example invalid
// sequences simply through collecting user command line arguments, for
// example.
#[cfg(unix)] {
use std::ffi::OsStr;
use std::os::unix::ffi::OsStrExt;
// Here, the values 0x66 and 0x6f correspond to 'f' and 'o'
// respectively. The value 0x80 is a lone continuation byte, invalid
// in a UTF-8 sequence.
let source = [0x66, 0x6f, 0x80, 0x6f];
let os_str = OsStr::from_bytes(&source[..]);
assert_eq!(os_str.to_string_lossy(), "fo�o");
}
#[cfg(windows)] {
use std::ffi::OsString;
use std::os::windows::prelude::*;
// Here the values 0x0066 and 0x006f correspond to 'f' and 'o'
// respectively. The value 0xD800 is a lone surrogate half, invalid
// in a UTF-16 sequence.
let source = [0x0066, 0x006f, 0xD800, 0x006f];
let os_string = OsString::from_wide(&source[..]);
let os_str = os_string.as_os_str();
assert_eq!(os_str.to_string_lossy(), "fo�o");
}
Checks whether the OsStr
is empty.
Examples
use std::ffi::OsStr;
let os_str = OsStr::new("");
assert!(os_str.is_empty());
let os_str = OsStr::new("foo");
assert!(!os_str.is_empty());
Returns the length of this OsStr
.
Note that this does not return the number of bytes in the string in OS string form.
The length returned is that of the underlying storage used by OsStr
.
As discussed in the OsString
introduction, OsString
and OsStr
store strings in a form best suited for cheap inter-conversion between
native-platform and Rust string forms, which may differ significantly
from both of them, including in storage size and encoding.
This number is simply useful for passing to other methods, like
OsString::with_capacity
to avoid reallocations.
Examples
use std::ffi::OsStr;
let os_str = OsStr::new("");
assert_eq!(os_str.len(), 0);
let os_str = OsStr::new("foo");
assert_eq!(os_str.len(), 3);
Converts this string to its ASCII lower case equivalent in-place.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To return a new lowercased value without modifying the existing one, use
OsStr::to_ascii_lowercase
.
Examples
use std::ffi::OsString;
let mut s = OsString::from("GRÜßE, JÜRGEN ❤");
s.make_ascii_lowercase();
assert_eq!("grÜße, jÜrgen ❤", s);
Converts this string to its ASCII upper case equivalent in-place.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To return a new uppercased value without modifying the existing one, use
OsStr::to_ascii_uppercase
.
Examples
use std::ffi::OsString;
let mut s = OsString::from("Grüße, Jürgen ❤");
s.make_ascii_uppercase();
assert_eq!("GRüßE, JüRGEN ❤", s);
Returns a copy of this string where each character is mapped to its ASCII lower case equivalent.
ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.
To lowercase the value in-place, use OsStr::make_ascii_lowercase
.
Examples
use std::ffi::OsString;
let s = OsString::from("Grüße, Jürgen ❤");
assert_eq!("grüße, jürgen ❤", s.to_ascii_lowercase());
Returns a copy of this string where each character is mapped to its ASCII upper case equivalent.
ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.
To uppercase the value in-place, use OsStr::make_ascii_uppercase
.
Examples
use std::ffi::OsString;
let s = OsString::from("Grüße, Jürgen ❤");
assert_eq!("GRüßE, JüRGEN ❤", s.to_ascii_uppercase());
Checks if all characters in this string are within the ASCII range.
Examples
use std::ffi::OsString;
let ascii = OsString::from("hello!\n");
let non_ascii = OsString::from("Grüße, Jürgen ❤");
assert!(ascii.is_ascii());
assert!(!non_ascii.is_ascii());
Checks that two strings are an ASCII case-insensitive match.
Same as to_ascii_lowercase(a) == to_ascii_lowercase(b)
,
but without allocating and copying temporaries.
Examples
use std::ffi::OsString;
assert!(OsString::from("Ferris").eq_ignore_ascii_case("FERRIS"));
assert!(OsString::from("Ferrös").eq_ignore_ascii_case("FERRöS"));
assert!(!OsString::from("Ferrös").eq_ignore_ascii_case("FERRÖS"));
Trait Implementations
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
pub fn from(s: OsString) -> Box<OsStr, Global>ⓘimpl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
pub fn from(s: OsString) -> Box<OsStr, Global>ⓘimpl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
impl<W> Write for Box<W, Global> where
W: Write + ?Sized, impl<R> Read for Box<R, Global> where
R: Read + ?Sized, impl<F, A> Future for Box<F, A> where
F: Future + Unpin + ?Sized,
A: Allocator + 'static, type Output = <F as Future>::Output;impl<I, A> Iterator for Box<I, A> where
I: Iterator + ?Sized,
A: Allocator, type Item = <I as Iterator>::Item;
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Auto Trait Implementations
impl RefUnwindSafe for OsString
impl UnwindSafe for OsString
Blanket Implementations
Mutably borrows from an owned value. Read more