# Struct clap::parser::ArgMatches

source · [−]

    pub struct ArgMatches { /* private fields */ }

Expand description

Container for parse results.

Used to get information about the arguments that were supplied to the program at runtime by the user. New instances of this struct are obtained by using the `Command::get_matches` family of methods.

## Examples

    let matches = Command::new("MyApp")
        .arg(Arg::new("out")
            .long("output")
            .required(true)
            .action(ArgAction::Set)
            .default_value("-"))
        .arg(Arg::new("cfg")
            .short('c')
            .action(ArgAction::Set))
        .get_matches(); // builds the instance of ArgMatches

    // to get information about the "cfg" argument we created, such as the value supplied we use
    // various ArgMatches methods, such as [ArgMatches::get_one]
    if let Some(c) = matches.get_one::<String>("cfg") {
        println!("Value for -c: {}", c);
    }

    // The ArgMatches::get_one method returns an Option because the user may not have supplied
    // that argument at runtime. But if we specified that the argument was "required" as we did
    // with the "out" argument, we can safely unwrap because `clap` verifies that was actually
    // used at runtime.
    println!("Value for --output: {}", matches.get_one::<String>("out").unwrap());

    // You can check the presence of an argument's values
    if matches.contains_id("out") {
        // However, if you want to know where the value came from
        if matches.value_source("out").expect("checked contains_id") == ValueSource::CommandLine {
            println!("`out` set by user");
        } else {
            println!("`out` is defaulted");
        }
    }

## Implementations

source

### impl ArgMatches

#### Arguments

source

#### pub fn get_one<T: Any + Clone + Send + Sync + 'static>(
&self,
id: &str
) -> Option<&T>

Gets the value of a specific option or positional argument.

i.e. an argument that takes an additional value at runtime.

Returns an error if the wrong type was used.

Returns `None` if the option wasn’t present.

NOTE: This will always return `Some(value)` if `default_value` has been set. `ArgMatches::value_source` can be used to check if a value is present at runtime.

##### Panic

If the argument definition and access mismatch. To handle this case programmatically, see `ArgMatches::try_get_one`.

##### Examples

    let m = Command::new("myapp")
        .arg(Arg::new("port")
            .value_parser(value_parser!(usize))
            .action(ArgAction::Set)
            .required(true))
        .get_matches_from(vec!["myapp", "2020"]);

    let port: usize = *m
        .get_one("port")
        .expect("`port`is required");
    assert_eq!(port, 2020);

source

#### pub fn get_count(&self, id: &str) -> u8

Gets the value of a specific `ArgAction::Count` flag

##### Panic

If the argument’s action is not `ArgAction::Count`

##### Examples

    let cmd = Command::new("mycmd")
        .arg(
            Arg::new("flag")
                .long("flag")
                .action(clap::ArgAction::Count)
        );

    let matches = cmd.clone().try_get_matches_from(["mycmd", "--flag", "--flag"]).unwrap();
    assert_eq!(
        matches.get_count("flag"),
        2
    );

source

#### pub fn get_flag(&self, id: &str) -> bool

Gets the value of a specific `ArgAction::SetTrue` or `ArgAction::SetFalse` flag

##### Panic

If the argument’s action is not `ArgAction::SetTrue` or `ArgAction::SetFalse`

##### Examples

    let cmd = Command::new("mycmd")
        .arg(
            Arg::new("flag")
                .long("flag")
                .action(clap::ArgAction::SetTrue)
        );

    let matches = cmd.clone().try_get_matches_from(["mycmd", "--flag"]).unwrap();
    assert!(matches.contains_id("flag"));
    assert_eq!(
        matches.get_flag("flag"),
        true
    );

source

#### pub fn get_many<T: Any + Clone + Send + Sync + 'static>(
&self,
id: &str
) -> Option<ValuesRef<'_, T>>

Iterate over values of a specific option or positional argument.

i.e. an argument that takes multiple values at runtime.

Returns an error if the wrong type was used.

Returns `None` if the option wasn’t present.

##### Panic

If the argument definition and access mismatch. To handle this case programmatically, see `ArgMatches::try_get_many`.

##### Examples

    let m = Command::new("myprog")
        .arg(Arg::new("ports")
            .action(ArgAction::Append)
            .value_parser(value_parser!(usize))
            .short('p')
            .required(true))
        .get_matches_from(vec![
            "myprog", "-p", "22", "-p", "80", "-p", "2020"
        ]);
    let vals: Vec<usize> = m.get_many("ports")
        .expect("`port`is required")
        .copied()
        .collect();
    assert_eq!(vals, [22, 80, 2020]);

source

#### pub fn get_raw(&self, id: &str) -> Option<RawValues<'_>>

Iterate over the original argument values.

An `OsStr` on Unix-like systems is any series of bytes, regardless of whether or not they contain valid UTF-8. Since `String`s in Rust are guaranteed to be valid UTF-8, a valid filename on a Unix system as an argument value may contain invalid UTF-8.

Returns `None` if the option wasn’t present.

##### Panic

If the argument definition and access mismatch. To handle this case programmatically, see `ArgMatches::try_get_raw`.

##### Examples

    use std::path::PathBuf;

    let m = Command::new("utf8")
       .arg(arg!(<arg> ... "some arg").value_parser(value_parser!(PathBuf)))
       .get_matches_from(vec![OsString::from("myprog"),
                                   // "Hi"
                                   OsString::from_vec(vec![b'H', b'i']),
                                   // "{0xe9}!"
                                   OsString::from_vec(vec![0xe9, b'!'])]);

    let mut itr = m.get_raw("arg")
       .expect("`port`is required")
       .into_iter();
    assert_eq!(itr.next(), Some(OsStr::new("Hi")));
    assert_eq!(itr.next(), Some(OsStr::from_bytes(&[0xe9, b'!'])));
    assert_eq!(itr.next(), None);

source

#### pub fn remove_one<T: Any + Clone + Send + Sync + 'static>(
&mut self,
id: &str
) -> Option<T>

Returns the value of a specific option or positional argument.

i.e. an argument that takes an additional value at runtime.

Returns an error if the wrong type was used. No item will have been removed.

Returns `None` if the option wasn’t present.

NOTE: This will always return `Some(value)` if `default_value` has been set. `ArgMatches::value_source` can be used to check if a value is present at runtime.

##### Panic

If the argument definition and access mismatch. To handle this case programmatically, see `ArgMatches::try_remove_one`.

##### Examples

    let mut m = Command::new("myprog")
        .arg(Arg::new("file")
            .required(true)
            .action(ArgAction::Set))
        .get_matches_from(vec![
            "myprog", "file.txt",
        ]);
    let vals: String = m.remove_one("file")
        .expect("`file`is required");
    assert_eq!(vals, "file.txt");

source

#### pub fn remove_many<T: Any + Clone + Send + Sync + 'static>(
&mut self,
id: &str
) -> Option<Values<T>>

Return values of a specific option or positional argument.

i.e. an argument that takes multiple values at runtime.

Returns an error if the wrong type was used. No item will have been removed.

Returns `None` if the option wasn’t present.

##### Panic

If the argument definition and access mismatch. To handle this case programmatically, see `ArgMatches::try_remove_many`.

##### Examples

    let mut m = Command::new("myprog")
        .arg(Arg::new("file")
            .action(ArgAction::Append)
            .num_args(1..)
            .required(true))
        .get_matches_from(vec![
            "myprog", "file1.txt", "file2.txt", "file3.txt", "file4.txt",
        ]);
    let vals: Vec<String> = m.remove_many("file")
        .expect("`file`is required")
        .collect();
    assert_eq!(vals, ["file1.txt", "file2.txt", "file3.txt", "file4.txt"]);

source

#### pub fn contains_id(&self, id: &str) -> bool

Check if values are present for the argument or group id

NOTE: This will always return `true` if `default_value` has been set. `ArgMatches::value_source` can be used to check if a value is present at runtime.

##### Panics

If `id` is is not a valid argument or group name. To handle this case programmatically, see `ArgMatches::try_contains_id`.

##### Examples

    let m = Command::new("myprog")
        .arg(Arg::new("debug")
            .short('d')
            .action(ArgAction::SetTrue))
        .get_matches_from(vec![
            "myprog", "-d"
        ]);

    assert!(m.contains_id("debug"));

source

#### pub fn ids(&self) -> IdsRef<'_>ⓘNotable traits for IdsRef<'a>`impl<'a> Iterator for IdsRef<'a> type Item = &'a Id;`

Iterate over `Arg` and `ArgGroup` `Id`s via `ArgMatches::ids`.

##### Examples

    let m = Command::new("myprog")
        .arg(arg!(--color <when>)
            .value_parser(["auto", "always", "never"]))
        .arg(arg!(--config <path>)
            .value_parser(value_parser!(std::path::PathBuf)))
        .get_matches_from(["myprog", "--config=config.toml", "--color=auto"]);
    assert_eq!(m.ids().len(), 2);
    assert_eq!(
        m.ids()
            .map(|id| id.as_str())
            .collect::<Vec<_>>(),
        ["config", "color"]
    );

source

#### pub fn args_present(&self) -> bool

Check if any args were present on the command line

##### Examples

    let mut cmd = Command::new("myapp")
        .arg(Arg::new("output")
            .action(ArgAction::Set));

    let m = cmd
        .try_get_matches_from_mut(vec!["myapp", "something"])
        .unwrap();
    assert!(m.args_present());

    let m = cmd
        .try_get_matches_from_mut(vec!["myapp"])
        .unwrap();
    assert!(! m.args_present());

source

#### pub fn value_source(&self, id: &str) -> Option<ValueSource>

Report where argument value came from

##### Panics

If `id` is is not a valid argument or group id.

##### Examples

    let m = Command::new("myprog")
        .arg(Arg::new("debug")
            .short('d')
            .action(ArgAction::SetTrue))
        .get_matches_from(vec![
            "myprog", "-d"
        ]);

    assert_eq!(m.value_source("debug"), Some(ValueSource::CommandLine));

source

#### pub fn index_of(&self, id: &str) -> Option<usize>

The first index of that an argument showed up.

Indices are similar to argv indices, but are not exactly 1:1.

For flags (i.e. those arguments which don’t have an associated value), indices refer to occurrence of the switch, such as `-f`, or `--flag`. However, for options the indices refer to the values `-o val` would therefore not represent two distinct indices, only the index for `val` would be recorded. This is by design.

Besides the flag/option discrepancy, the primary difference between an argv index and clap index, is that clap continues counting once all arguments have properly separated, whereas an argv index does not.

The examples should clear this up.

NOTE: If an argument is allowed multiple times, this method will only give the first index. See `ArgMatches::indices_of`.

##### Panics

If `id` is is not a valid argument or group id.

##### Examples

The argv indices are listed in the comments below. See how they correspond to the clap indices. Note that if it’s not listed in a clap index, this is because it’s not saved in in an `ArgMatches` struct for querying.

    let m = Command::new("myapp")
        .arg(Arg::new("flag")
            .short('f')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set))
        .get_matches_from(vec!["myapp", "-f", "-o", "val"]);
               // ARGV indices: ^0       ^1    ^2    ^3
               // clap indices:          ^1          ^3

    assert_eq!(m.index_of("flag"), Some(1));
    assert_eq!(m.index_of("option"), Some(3));

Now notice, if we use one of the other styles of options:

    let m = Command::new("myapp")
        .arg(Arg::new("flag")
            .short('f')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set))
        .get_matches_from(vec!["myapp", "-f", "-o=val"]);
               // ARGV indices: ^0       ^1    ^2
               // clap indices:          ^1       ^3

    assert_eq!(m.index_of("flag"), Some(1));
    assert_eq!(m.index_of("option"), Some(3));

Things become much more complicated, or clear if we look at a more complex combination of flags. Let’s also throw in the final option style for good measure.

    let m = Command::new("myapp")
        .arg(Arg::new("flag")
            .short('f')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("flag2")
            .short('F')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("flag3")
            .short('z')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set))
        .get_matches_from(vec!["myapp", "-fzF", "-oval"]);
               // ARGV indices: ^0      ^1       ^2
               // clap indices:         ^1,2,3    ^5
               //
               // clap sees the above as 'myapp -f -z -F -o val'
               //                         ^0    ^1 ^2 ^3 ^4 ^5
    assert_eq!(m.index_of("flag"), Some(1));
    assert_eq!(m.index_of("flag2"), Some(3));
    assert_eq!(m.index_of("flag3"), Some(2));
    assert_eq!(m.index_of("option"), Some(5));

One final combination of flags/options to see how they combine:

    let m = Command::new("myapp")
        .arg(Arg::new("flag")
            .short('f')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("flag2")
            .short('F')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("flag3")
            .short('z')
            .action(ArgAction::SetTrue))
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set))
        .get_matches_from(vec!["myapp", "-fzFoval"]);
               // ARGV indices: ^0       ^1
               // clap indices:          ^1,2,3^5
               //
               // clap sees the above as 'myapp -f -z -F -o val'
               //                         ^0    ^1 ^2 ^3 ^4 ^5
    assert_eq!(m.index_of("flag"), Some(1));
    assert_eq!(m.index_of("flag2"), Some(3));
    assert_eq!(m.index_of("flag3"), Some(2));
    assert_eq!(m.index_of("option"), Some(5));

The last part to mention is when values are sent in multiple groups with a delimiter.

    let m = Command::new("myapp")
        .arg(Arg::new("option")
            .short('o')
            .value_delimiter(',')
            .num_args(1..))
        .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
               // ARGV indices: ^0       ^1
               // clap indices:             ^2   ^3   ^4
               //
               // clap sees the above as 'myapp -o val1 val2 val3'
               //                         ^0    ^1 ^2   ^3   ^4
    assert_eq!(m.index_of("option"), Some(2));
    assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 3, 4]);

source

#### pub fn indices_of(&self, id: &str) -> Option<Indices<'_>>

All indices an argument appeared at when parsing.

Indices are similar to argv indices, but are not exactly 1:1.

For flags (i.e. those arguments which don’t have an associated value), indices refer to occurrence of the switch, such as `-f`, or `--flag`. However, for options the indices refer to the values `-o val` would therefore not represent two distinct indices, only the index for `val` would be recorded. This is by design.

NOTE: For more information about how clap indices compared to argv indices, see `ArgMatches::index_of`

##### Panics

If `id` is is not a valid argument or group id.

##### Examples

    let m = Command::new("myapp")
        .arg(Arg::new("option")
            .short('o')
            .value_delimiter(','))
        .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
               // ARGV indices: ^0       ^1
               // clap indices:             ^2   ^3   ^4
               //
               // clap sees the above as 'myapp -o val1 val2 val3'
               //                         ^0    ^1 ^2   ^3   ^4
    assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 3, 4]);

Another quick example is when flags and options are used together

    let m = Command::new("myapp")
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set)
            .action(ArgAction::Append))
        .arg(Arg::new("flag")
            .short('f')
            .action(ArgAction::Count))
        .get_matches_from(vec!["myapp", "-o", "val1", "-f", "-o", "val2", "-f"]);
               // ARGV indices: ^0       ^1    ^2      ^3    ^4    ^5      ^6
               // clap indices:                ^2      ^3          ^5      ^6

    assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2, 5]);
    assert_eq!(m.indices_of("flag").unwrap().collect::<Vec<_>>(), &[6]);

One final example, which is an odd case; if we don’t use value delimiter as we did with the first example above instead of `val1`, `val2` and `val3` all being distinc values, they would all be a single value of `val1,val2,val3`, in which case they’d only receive a single index.

    let m = Command::new("myapp")
        .arg(Arg::new("option")
            .short('o')
            .action(ArgAction::Set)
            .num_args(1..))
        .get_matches_from(vec!["myapp", "-o=val1,val2,val3"]);
               // ARGV indices: ^0       ^1
               // clap indices:             ^2
               //
               // clap sees the above as 'myapp -o "val1,val2,val3"'
               //                         ^0    ^1  ^2
    assert_eq!(m.indices_of("option").unwrap().collect::<Vec<_>>(), &[2]);

source

### impl ArgMatches

#### Subcommands

source

#### pub fn subcommand(&self) -> Option<(&str, &ArgMatches)>

The name and `ArgMatches` of the current subcommand.

Subcommand values are put in a child `ArgMatches`

Returns `None` if the subcommand wasn’t present at runtime,

##### Examples

     let app_m = Command::new("git")
         .subcommand(Command::new("clone"))
         .subcommand(Command::new("push"))
         .subcommand(Command::new("commit"))
         .get_matches();

    match app_m.subcommand() {
        Some(("clone",  sub_m)) => {}, // clone was used
        Some(("push",   sub_m)) => {}, // push was used
        Some(("commit", sub_m)) => {}, // commit was used
        _                       => {}, // Either no subcommand or one not tested for...
    }

Another useful scenario is when you want to support third party, or external, subcommands. In these cases you can’t know the subcommand name ahead of time, so use a variable instead with pattern matching!

    // Assume there is an external subcommand named "subcmd"
    let app_m = Command::new("myprog")
        .allow_external_subcommands(true)
        .get_matches_from(vec![
            "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ]);

    // All trailing arguments will be stored under the subcommand's sub-matches using an empty
    // string argument name
    match app_m.subcommand() {
        Some((external, sub_m)) => {
             let ext_args: Vec<&OsStr> = sub_m.get_many::<OsString>("")
                .unwrap().map(|s| s.as_os_str()).collect();
             assert_eq!(external, "subcmd");
             assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        },
        _ => {},
    }

source

#### pub fn remove_subcommand(&mut self) -> Option<(String, ArgMatches)>

Return the name and `ArgMatches` of the current subcommand.

Subcommand values are put in a child `ArgMatches`

Returns `None` if the subcommand wasn’t present at runtime,

##### Examples

     let mut app_m = Command::new("git")
         .subcommand(Command::new("clone"))
         .subcommand(Command::new("push"))
         .subcommand(Command::new("commit"))
         .subcommand_required(true)
         .get_matches();

    let (name, sub_m) = app_m.remove_subcommand().expect("required");
    match (name.as_str(), sub_m) {
        ("clone",  sub_m) => {}, // clone was used
        ("push",   sub_m) => {}, // push was used
        ("commit", sub_m) => {}, // commit was used
        (name, _)         => unimplemented!("{}", name),
    }

Another useful scenario is when you want to support third party, or external, subcommands. In these cases you can’t know the subcommand name ahead of time, so use a variable instead with pattern matching!

    // Assume there is an external subcommand named "subcmd"
    let mut app_m = Command::new("myprog")
        .allow_external_subcommands(true)
        .get_matches_from(vec![
            "myprog", "subcmd", "--option", "value", "-fff", "--flag"
        ]);

    // All trailing arguments will be stored under the subcommand's sub-matches using an empty
    // string argument name
    match app_m.remove_subcommand() {
        Some((external, mut sub_m)) => {
             let ext_args: Vec<OsString> = sub_m.remove_many("")
                .expect("`file`is required")
                .collect();
             assert_eq!(external, "subcmd");
             assert_eq!(ext_args, ["--option", "value", "-fff", "--flag"]);
        },
        _ => {},
    }

source

#### pub fn subcommand_matches(&self, name: &str) -> Option<&ArgMatches>

The `ArgMatches` for the current subcommand.

Subcommand values are put in a child `ArgMatches`

Returns `None` if the subcommand wasn’t present at runtime,

##### Panics

If `id` is is not a valid subcommand.

##### Examples

    let app_m = Command::new("myprog")
        .arg(Arg::new("debug")
            .short('d')
            .action(ArgAction::SetTrue)
        )
        .subcommand(Command::new("test")
            .arg(Arg::new("opt")
                .long("option")
                .action(ArgAction::Set)))
        .get_matches_from(vec![
            "myprog", "-d", "test", "--option", "val"
        ]);

    // Both parent commands, and child subcommands can have arguments present at the same times
    assert!(*app_m.get_one::<bool>("debug").expect("defaulted by clap"));

    // Get the subcommand's ArgMatches instance
    if let Some(sub_m) = app_m.subcommand_matches("test") {
        // Use the struct like normal
        assert_eq!(sub_m.get_one::<String>("opt").map(|s| s.as_str()), Some("val"));
    }

source

#### pub fn subcommand_name(&self) -> Option<&str>

The name of the current subcommand.

Returns `None` if the subcommand wasn’t present at runtime,

##### Examples

     let app_m = Command::new("git")
         .subcommand(Command::new("clone"))
         .subcommand(Command::new("push"))
         .subcommand(Command::new("commit"))
         .get_matches();

    match app_m.subcommand_name() {
        Some("clone")  => {}, // clone was used
        Some("push")   => {}, // push was used
        Some("commit") => {}, // commit was used
        _              => {}, // Either no subcommand or one not tested for...
    }

source

### impl ArgMatches

#### Advanced

source

#### pub fn try_get_one<T: Any + Clone + Send + Sync + 'static>(
&self,
id: &str
) -> Result<Option<&T>, MatchesError>

Non-panicking version of `ArgMatches::get_one`

source

#### pub fn try_get_many<T: Any + Clone + Send + Sync + 'static>(
&self,
id: &str
) -> Result<Option<ValuesRef<'_, T>>, MatchesError>

Non-panicking version of `ArgMatches::get_many`

source

#### pub fn try_get_raw(
&self,
id: &str
) -> Result<Option<RawValues<'_>>, MatchesError>

Non-panicking version of `ArgMatches::get_raw`

source

#### pub fn try_remove_one<T: Any + Clone + Send + Sync + 'static>(
&mut self,
id: &str
) -> Result<Option<T>, MatchesError>

Non-panicking version of `ArgMatches::remove_one`

source

#### pub fn try_remove_many<T: Any + Clone + Send + Sync + 'static>(
&mut self,
id: &str
) -> Result<Option<Values<T>>, MatchesError>

Non-panicking version of `ArgMatches::remove_many`

source

#### pub fn try_contains_id(&self, id: &str) -> Result<bool, MatchesError>

Non-panicking version of `ArgMatches::contains_id`

## Trait Implementations

source

### impl Clone for ArgMatches

source

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

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

source

### impl Debug for ArgMatches

source

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

Formats the value using the given formatter. Read more

source

### impl Default for ArgMatches

source

#### fn default() -> ArgMatches

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

source

### impl PartialEq<ArgMatches> for ArgMatches

source

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

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

source

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

This method tests for `!=`.

source

### impl Eq for ArgMatches

source

### impl StructuralEq for ArgMatches

source

### impl StructuralPartialEq for ArgMatches

## Auto Trait Implementations

### impl !RefUnwindSafe for ArgMatches

### impl Send for ArgMatches

### impl Sync for ArgMatches

### impl Unpin for ArgMatches

### impl !UnwindSafe for ArgMatches

## Blanket Implementations

source

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

source

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

Gets the `TypeId` of `self`. Read more

source

### impl<T> Borrow<T> for T where
T: ?Sized,

const: unstable · source

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

Immutably borrows from an owned value. Read more

source

### impl<T> BorrowMut<T> for T where
T: ?Sized,

const: unstable · source

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

Mutably borrows from an owned value. Read more

source

### impl<T> From<T> for T

const: unstable · source

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

Returns the argument unchanged.

source

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

const: unstable · source

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

Calls `U::from(self)`.

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

source

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

#### type Owned = T

The resulting type after obtaining ownership.

source

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

Creates owned data from borrowed data, usually by cloning. Read more

source

#### fn clone_into(&self, target: &mut T)

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

source

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

#### type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.

source

### impl<T, U> TryInto<U> for T where
U: TryFrom<T>,

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

The type returned in the event of a conversion error.

const: unstable · source

#### fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.