PathBuf in std::path - Rust (original) (raw)

pub struct PathBuf { /* private fields */ }

Expand description

An owned, mutable path (akin to String).

This type provides methods like push and set_extension that mutate the path in place. It also implements Deref to Path, meaning that all methods on Path slices are available on PathBuf values as well.

More details about the overall approach can be found in the module documentation.

You can use push to build up a PathBuf from components:

use std::path::PathBuf;

let mut path = PathBuf::new();

path.push(r"C:\");
path.push("windows");
path.push("system32");

path.set_extension("dll");

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However, push is best used for dynamic situations. This is a better way to do this when you know all of the components ahead of time:

use std::path::PathBuf;

let path: PathBuf = [r"C:\", "windows", "system32.dll"].iter().collect();

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We can still do better than this! Since these are all strings, we can useFrom::from:

use std::path::PathBuf;

let path = PathBuf::from(r"C:\windows\system32.dll");

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Which method works best depends on what kind of situation you’re in.

Allocates an empty PathBuf.

use std::path::PathBuf;

let path = PathBuf::new();

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Creates a new PathBuf with a given capacity used to create the internal OsString. See with_capacity defined on OsString.

use std::path::PathBuf;

let mut path = PathBuf::with_capacity(10);
let capacity = path.capacity();

// This push is done without reallocating
path.push(r"C:\");

assert_eq!(capacity, path.capacity());

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Coerces to a Path slice.

use std::path::{Path, PathBuf};

let p = PathBuf::from("/test");
assert_eq!(Path::new("/test"), p.as_path());

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Extends self with path.

If path is absolute, it replaces the current path.

On Windows:

if path has a root but no prefix (e.g., \windows), it replaces everything except for the prefix (if any) of self.
if path has a prefix but no root, it replaces self.
if self has a verbatim prefix (e.g. \\?\C:\windows) and path is not empty, the new path is normalized: all references to . and .. are removed.

Pushing a relative path extends the existing path:

use std::path::PathBuf;

let mut path = PathBuf::from("/tmp");
path.push("file.bk");
assert_eq!(path, PathBuf::from("/tmp/file.bk"));

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Pushing an absolute path replaces the existing path:

use std::path::PathBuf;

let mut path = PathBuf::from("/tmp");
path.push("/etc");
assert_eq!(path, PathBuf::from("/etc"));

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Truncates self to self.parent.

Returns false and does nothing if self.parent is None. Otherwise, returns true.

use std::path::{Path, PathBuf};

let mut p = PathBuf::from("/spirited/away.rs");

p.pop();
assert_eq!(Path::new("/spirited"), p);
p.pop();
assert_eq!(Path::new("/"), p);

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Updates self.file_name to file_name.

If self.file_name was None, this is equivalent to pushingfile_name.

Otherwise it is equivalent to calling pop and then pushingfile_name. The new path will be a sibling of the original path. (That is, it will have the same parent.)

use std::path::PathBuf;

let mut buf = PathBuf::from("/");
assert!(buf.file_name() == None);
buf.set_file_name("bar");
assert!(buf == PathBuf::from("/bar"));
assert!(buf.file_name().is_some());
buf.set_file_name("baz.txt");
assert!(buf == PathBuf::from("/baz.txt"));

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Updates self.extension to extension.

Returns false and does nothing if self.file_name is None, returns true and updates the extension otherwise.

If self.extension is None, the extension is added; otherwise it is replaced.

use std::path::{Path, PathBuf};

let mut p = PathBuf::from("/feel/the");

p.set_extension("force");
assert_eq!(Path::new("/feel/the.force"), p.as_path());

p.set_extension("dark_side");
assert_eq!(Path::new("/feel/the.dark_side"), p.as_path());

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Consumes the PathBuf, yielding its internal OsString storage.

use std::path::PathBuf;

let p = PathBuf::from("/the/head");
let os_str = p.into_os_string();

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Converts this PathBuf into a boxed Path.

Invokes clear on the underlying instance of OsString.

Yields the underlying OsStr slice.

use std::path::Path;

let os_str = Path::new("foo.txt").as_os_str();
assert_eq!(os_str, std::ffi::OsStr::new("foo.txt"));

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Yields a &str slice if the Path is valid unicode.

This conversion may entail doing a check for UTF-8 validity. Note that validation is performed because non-UTF-8 strings are perfectly valid for some OS.

use std::path::Path;

let path = Path::new("foo.txt");
assert_eq!(path.to_str(), Some("foo.txt"));

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Converts a Path to a Cow.

Any non-Unicode sequences are replaced withU+FFFD REPLACEMENT CHARACTER.

Calling to_string_lossy on a Path with valid unicode:

use std::path::Path;

let path = Path::new("foo.txt");
assert_eq!(path.to_string_lossy(), "foo.txt");

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Had path contained invalid unicode, the to_string_lossy call might have returned "fo�.txt".

Converts a Path to an owned PathBuf.

use std::path::Path;

let path_buf = Path::new("foo.txt").to_path_buf();
assert_eq!(path_buf, std::path::PathBuf::from("foo.txt"));

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Returns true if the Path is absolute, i.e., if it is independent of the current directory.

On Unix, a path is absolute if it starts with the root, sois_absolute and has_root are equivalent.
On Windows, a path is absolute if it has a prefix and starts with the root: c:\windows is absolute, while c:temp and \temp are not.

use std::path::Path;

assert!(!Path::new("foo.txt").is_absolute());

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Returns true if the Path is relative, i.e., not absolute.

See is_absolute’s documentation for more details.

use std::path::Path;

assert!(Path::new("foo.txt").is_relative());

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Returns true if the Path has a root.

On Unix, a path has a root if it begins with /.
On Windows, a path has a root if it:
- has no prefix and begins with a separator, e.g., \windows
- has a prefix followed by a separator, e.g., c:\windows but not c:windows
- has any non-disk prefix, e.g., \\server\share

use std::path::Path;

assert!(Path::new("/etc/passwd").has_root());

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Returns the Path without its final component, if there is one.

Returns None if the path terminates in a root or prefix.

use std::path::Path;

let path = Path::new("/foo/bar");
let parent = path.parent().unwrap();
assert_eq!(parent, Path::new("/foo"));

let grand_parent = parent.parent().unwrap();
assert_eq!(grand_parent, Path::new("/"));
assert_eq!(grand_parent.parent(), None);

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Produces an iterator over Path and its ancestors.

The iterator will yield the Path that is returned if the parent method is used zero or more times. That means, the iterator will yield &self, &self.parent().unwrap(),&self.parent().unwrap().parent().unwrap() and so on. If the parent method returnsNone, the iterator will do likewise. The iterator will always yield at least one value, namely &self.

use std::path::Path;

let mut ancestors = Path::new("/foo/bar").ancestors();
assert_eq!(ancestors.next(), Some(Path::new("/foo/bar")));
assert_eq!(ancestors.next(), Some(Path::new("/foo")));
assert_eq!(ancestors.next(), Some(Path::new("/")));
assert_eq!(ancestors.next(), None);

let mut ancestors = Path::new("../foo/bar").ancestors();
assert_eq!(ancestors.next(), Some(Path::new("../foo/bar")));
assert_eq!(ancestors.next(), Some(Path::new("../foo")));
assert_eq!(ancestors.next(), Some(Path::new("..")));
assert_eq!(ancestors.next(), Some(Path::new("")));
assert_eq!(ancestors.next(), None);

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Returns the final component of the Path, if there is one.

If the path is a normal file, this is the file name. If it’s the path of a directory, this is the directory name.

Returns None if the path terminates in ...

use std::path::Path;
use std::ffi::OsStr;

assert_eq!(Some(OsStr::new("bin")), Path::new("/usr/bin/").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("tmp/foo.txt").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.").file_name());
assert_eq!(Some(OsStr::new("foo.txt")), Path::new("foo.txt/.//").file_name());
assert_eq!(None, Path::new("foo.txt/..").file_name());
assert_eq!(None, Path::new("/").file_name());

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Returns a path that, when joined onto base, yields self.

If base is not a prefix of self (i.e., starts_withreturns false), returns Err.

use std::path::{Path, PathBuf};

let path = Path::new("/test/haha/foo.txt");

assert_eq!(path.strip_prefix("/"), Ok(Path::new("test/haha/foo.txt")));
assert_eq!(path.strip_prefix("/test"), Ok(Path::new("haha/foo.txt")));
assert_eq!(path.strip_prefix("/test/"), Ok(Path::new("haha/foo.txt")));
assert_eq!(path.strip_prefix("/test/haha/foo.txt"), Ok(Path::new("")));
assert_eq!(path.strip_prefix("/test/haha/foo.txt/"), Ok(Path::new("")));

assert!(path.strip_prefix("test").is_err());
assert!(path.strip_prefix("/haha").is_err());

let prefix = PathBuf::from("/test/");
assert_eq!(path.strip_prefix(prefix), Ok(Path::new("haha/foo.txt")));

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Determines whether base is a prefix of self.

Only considers whole path components to match.

use std::path::Path;

let path = Path::new("/etc/passwd");

assert!(path.starts_with("/etc"));
assert!(path.starts_with("/etc/"));
assert!(path.starts_with("/etc/passwd"));
assert!(path.starts_with("/etc/passwd/")); // extra slash is okay
assert!(path.starts_with("/etc/passwd///")); // multiple extra slashes are okay

assert!(!path.starts_with("/e"));
assert!(!path.starts_with("/etc/passwd.txt"));

assert!(!Path::new("/etc/foo.rs").starts_with("/etc/foo"));

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Determines whether child is a suffix of self.

Only considers whole path components to match.

use std::path::Path;

let path = Path::new("/etc/resolv.conf");

assert!(path.ends_with("resolv.conf"));
assert!(path.ends_with("etc/resolv.conf"));
assert!(path.ends_with("/etc/resolv.conf"));

assert!(!path.ends_with("/resolv.conf"));
assert!(!path.ends_with("conf")); // use .extension() instead

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Extracts the stem (non-extension) portion of self.file_name.

The stem is:

None, if there is no file name;
The entire file name if there is no embedded .;
The entire file name if the file name begins with . and has no other .s within;
Otherwise, the portion of the file name before the final .

use std::path::Path;

assert_eq!("foo", Path::new("foo.rs").file_stem().unwrap());
assert_eq!("foo.tar", Path::new("foo.tar.gz").file_stem().unwrap());

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This method is similar to Path::file_prefix, which extracts the portion of the file name before the first .

🔬 This is a nightly-only experimental API. (path_file_prefix #86319)

Extracts the prefix of self.file_name.

The prefix is:

None, if there is no file name;
The entire file name if there is no embedded .;
The portion of the file name before the first non-beginning .;
The entire file name if the file name begins with . and has no other .s within;
The portion of the file name before the second . if the file name begins with .

use std::path::Path;

assert_eq!("foo", Path::new("foo.rs").file_prefix().unwrap());
assert_eq!("foo", Path::new("foo.tar.gz").file_prefix().unwrap());

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This method is similar to Path::file_stem, which extracts the portion of the file name before the last .

Extracts the extension of self.file_name, if possible.

The extension is:

None, if there is no file name;
None, if there is no embedded .;
None, if the file name begins with . and has no other .s within;
Otherwise, the portion of the file name after the final .

use std::path::Path;

assert_eq!("rs", Path::new("foo.rs").extension().unwrap());
assert_eq!("gz", Path::new("foo.tar.gz").extension().unwrap());

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Creates an owned PathBuf with path adjoined to self.

See PathBuf::push for more details on what it means to adjoin a path.

use std::path::{Path, PathBuf};

assert_eq!(Path::new("/etc").join("passwd"), PathBuf::from("/etc/passwd"));

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Creates an owned PathBuf like self but with the given file name.

See PathBuf::set_file_name for more details.

use std::path::{Path, PathBuf};

let path = Path::new("/tmp/foo.txt");
assert_eq!(path.with_file_name("bar.txt"), PathBuf::from("/tmp/bar.txt"));

let path = Path::new("/tmp");
assert_eq!(path.with_file_name("var"), PathBuf::from("/var"));

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Creates an owned PathBuf like self but with the given extension.

See PathBuf::set_extension for more details.

use std::path::{Path, PathBuf};

let path = Path::new("foo.rs");
assert_eq!(path.with_extension("txt"), PathBuf::from("foo.txt"));

let path = Path::new("foo.tar.gz");
assert_eq!(path.with_extension(""), PathBuf::from("foo.tar"));
assert_eq!(path.with_extension("xz"), PathBuf::from("foo.tar.xz"));
assert_eq!(path.with_extension("").with_extension("txt"), PathBuf::from("foo.txt"));

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Produces an iterator over the Components of the path.

When parsing the path, there is a small amount of normalization:

Repeated separators are ignored, so a/b and a//b both havea and b as components.
Occurrences of . are normalized away, except if they are at the beginning of the path. For example, a/./b, a/b/, a/b/. anda/b all have a and b as components, but ./a/b starts with an additional CurDir component.
A trailing slash is normalized away, /a/b and /a/b/ are equivalent.

Note that no other normalization takes place; in particular, a/cand a/b/../c are distinct, to account for the possibility that bis a symbolic link (so its parent isn’t a).

use std::path::{Path, Component};
use std::ffi::OsStr;

let mut components = Path::new("/tmp/foo.txt").components();

assert_eq!(components.next(), Some(Component::RootDir));
assert_eq!(components.next(), Some(Component::Normal(OsStr::new("tmp"))));
assert_eq!(components.next(), Some(Component::Normal(OsStr::new("foo.txt"))));
assert_eq!(components.next(), None)

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Produces an iterator over the path’s components viewed as OsStrslices.

For more information about the particulars of how the path is separated into components, see components.

use std::path::{self, Path};
use std::ffi::OsStr;

let mut it = Path::new("/tmp/foo.txt").iter();
assert_eq!(it.next(), Some(OsStr::new(&path::MAIN_SEPARATOR.to_string())));
assert_eq!(it.next(), Some(OsStr::new("tmp")));
assert_eq!(it.next(), Some(OsStr::new("foo.txt")));
assert_eq!(it.next(), None)

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Returns an object that implements Display for safely printing paths that may contain non-Unicode data. This may perform lossy conversion, depending on the platform. If you would like an implementation which escapes the path please use Debug instead.

use std::path::Path;

let path = Path::new("/tmp/foo.rs");

println!("{}", path.display());

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Queries the file system to get information about a file, directory, etc.

This function will traverse symbolic links to query information about the destination file.

This is an alias to fs::metadata.

use std::path::Path;

let path = Path::new("/Minas/tirith");
let metadata = path.metadata().expect("metadata call failed");
println!("{:?}", metadata.file_type());

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Queries the metadata about a file without following symlinks.

This is an alias to fs::symlink_metadata.

use std::path::Path;

let path = Path::new("/Minas/tirith");
let metadata = path.symlink_metadata().expect("symlink_metadata call failed");
println!("{:?}", metadata.file_type());

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Returns the canonical, absolute form of the path with all intermediate components normalized and symbolic links resolved.

This is an alias to fs::canonicalize.

use std::path::{Path, PathBuf};

let path = Path::new("/foo/test/../test/bar.rs");
assert_eq!(path.canonicalize().unwrap(), PathBuf::from("/foo/test/bar.rs"));

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Reads a symbolic link, returning the file that the link points to.

This is an alias to fs::read_link.

use std::path::Path;

let path = Path::new("/laputa/sky_castle.rs");
let path_link = path.read_link().expect("read_link call failed");

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Returns an iterator over the entries within a directory.

The iterator will yield instances of [io::Result](../io/type.Result.html "io::Result")<[fs::DirEntry](../fs/struct.DirEntry.html "fs::DirEntry")>. New errors may be encountered after an iterator is initially constructed.

This is an alias to fs::read_dir.

use std::path::Path;

let path = Path::new("/laputa");
for entry in path.read_dir().expect("read_dir call failed") {
    if let Ok(entry) = entry {
        println!("{:?}", entry.path());
    }
}

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Returns true if the path points at an existing entity.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

use std::path::Path;
assert!(!Path::new("does_not_exist.txt").exists());

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This is a convenience function that coerces errors to false. If you want to check errors, call fs::metadata.

🔬 This is a nightly-only experimental API. (path_try_exists #83186)

Returns Ok(true) if the path points at an existing entity.

This function will traverse symbolic links to query information about the destination file. In case of broken symbolic links this will return Ok(false).

As opposed to the exists() method, this one doesn’t silently ignore errors unrelated to the path not existing. (E.g. it will return Err(_) in case of permission denied on some of the parent directories.)

#![feature(path_try_exists)]

use std::path::Path;
assert!(!Path::new("does_not_exist.txt").try_exists().expect("Can't check existence of file does_not_exist.txt"));
assert!(Path::new("/root/secret_file.txt").try_exists().is_err());

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Returns true if the path exists on disk and is pointing at a regular file.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

use std::path::Path;
assert_eq!(Path::new("./is_a_directory/").is_file(), false);
assert_eq!(Path::new("a_file.txt").is_file(), true);

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This is a convenience function that coerces errors to false. If you want to check errors, call fs::metadata and handle its Result. Then callfs::Metadata::is_file if it was Ok.

When the goal is simply to read from (or write to) the source, the most reliable way to test the source can be read (or written to) is to open it. Only using is_file can break workflows like diff <( prog_a ) on a Unix-like system for example. See fs::File::open orfs::OpenOptions::open for more information.

Returns true if the path exists on disk and is pointing at a directory.

This function will traverse symbolic links to query information about the destination file.

If you cannot access the metadata of the file, e.g. because of a permission error or broken symbolic links, this will return false.

use std::path::Path;
assert_eq!(Path::new("./is_a_directory/").is_dir(), true);
assert_eq!(Path::new("a_file.txt").is_dir(), false);

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This is a convenience function that coerces errors to false. If you want to check errors, call fs::metadata and handle its Result. Then callfs::Metadata::is_dir if it was Ok.

Returns true if the path exists on disk and is pointing at a symbolic link.

This function will not traverse symbolic links. In case of a broken symbolic link this will also return true.

If you cannot access the directory containing the file, e.g., because of a permission error, this will return false.

use std::path::Path;
use std::os::unix::fs::symlink;

let link_path = Path::new("link");
symlink("/origin_does_not_exist/", link_path).unwrap();
assert_eq!(link_path.is_symlink(), true);
assert_eq!(link_path.exists(), false);

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This is a convenience function that coerces errors to false. If you want to check errors, call fs::symlink_metadata and handle its Result. Then callfs::Metadata::is_symlink if it was Ok.

Immutably borrows from an owned value. Read more

Formats the value using the given formatter. Read more

Returns the “default value” for a type. Read more

The resulting type after dereferencing.

Dereferences the value.

Extends a collection with the contents of an iterator. Read more

🔬 This is a nightly-only experimental API. (extend_one #72631)

Extends a collection with exactly one element.

🔬 This is a nightly-only experimental API. (extend_one #72631)

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

Converts a borrowed OsStr to a PathBuf.

Allocates a PathBuf and copies the data into it.

Creates a clone-on-write pointer from a reference toPathBuf.

This conversion does not clone or allocate.

Converts a Box<Path> into a PathBuf

This conversion does not allocate or copy memory.

Converts a clone-on-write pointer to an owned path.

Converting from a Cow::Owned does not clone or allocate.

Converts an OsString into a PathBuf

This conversion does not allocate or copy memory.

Converts a PathBuf into a Box<Path>

This conversion currently should not allocate memory, but this behavior is not guaranteed on all platforms or in all future versions.

Converts a PathBuf into an OsString

This conversion does not allocate or copy memory.

Creates a clone-on-write pointer from an owned instance of PathBuf.

This conversion does not clone or allocate.

Converts a String into a PathBuf

This conversion does not allocate or copy memory.

The associated error which can be returned from parsing.

Parses a string s to return a value of this type. Read more

The type of the elements being iterated over.

Which kind of iterator are we turning this into?

Creates an iterator from a value. Read more

Compares and returns the maximum of two values. Read more

Compares and returns the minimum of two values. Read more

Restrict a value to a certain interval. Read more

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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

This method tests for !=.

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