```
pub trait Arbitrary: Sized + Debug {
type Parameters: Default;
type Strategy: Strategy<Value = Self>;
// Required method
fn arbitrary_with(args: Self::Parameters) -> Self::Strategy;
// Provided method
fn arbitrary() -> Self::Strategy { ... }
}
```

## Expand description

Arbitrary determines a canonical `Strategy`

for the implementing type.

It provides the method `arbitrary_with`

which generates a `Strategy`

for
producing arbitrary values of the implementing type *( Self)*. In general,
these strategies will produce the entire set of values possible for the
type, up to some size limitation or constraints set by their parameters.
When this is not desired, strategies to produce the desired values can be
built by combining

`Strategy`

s as described in the crate documentation.This trait analogous to
Haskell QuickCheck’s implementation of `Arbitrary`

.
In this interpretation of `Arbitrary`

, `Strategy`

is the equivalent of
the `Gen`

monad. Unlike in QuickCheck, `Arbitrary`

is not a core component;
types do not need to implement `Arbitrary`

unless one wants to use
`any`

or other free functions in this module.

`Arbitrary`

currently only works for types which represent owned data as
opposed to borrowed data. This is a fundamental restriction of `proptest`

which may be lifted in the future as the generic associated types (GAT)
feature of Rust is implemented and stabilized.

## Required Associated Types§

source#### type Parameters: Default

#### type Parameters: Default

The type of parameters that `arbitrary_with`

accepts for configuration
of the generated `Strategy`

. Parameters must implement `Default`

.

## Required Methods§

source#### fn arbitrary_with(args: Self::Parameters) -> Self::Strategy

#### fn arbitrary_with(args: Self::Parameters) -> Self::Strategy

## Provided Methods§

source#### fn arbitrary() -> Self::Strategy

#### fn arbitrary() -> Self::Strategy

Generates a `Strategy`

for producing arbitrary values
of type the implementing type (`Self`

).

Calling this for the type `X`

is the equivalent of using
`X::arbitrary_with(Default::default())`

.

This method is defined in the trait for optimization for the default if you want to do that. It is a logic error to not preserve the semantics when overriding.

## Object Safety§

**not**object safe.

## Implementations on Foreign Types§

source§### impl Arbitrary for SocketAddr

### impl Arbitrary for SocketAddr

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<MapInto<<SocketAddrV4 as Arbitrary>::Strategy, SocketAddr>>), (u32, Arc<MapInto<<SocketAddrV6 as Arbitrary>::Strategy, SocketAddr>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for FpCategory

### impl Arbitrary for FpCategory

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<Just<FpCategory>>), (u32, Arc<Just<FpCategory>>), (u32, Arc<Just<FpCategory>>), (u32, Arc<Just<FpCategory>>), (u32, Arc<Just<FpCategory>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for Option<ParseError>

### impl Arbitrary for Option<ParseError>

#### type Parameters = ()

#### type Strategy = Just<Option<Infallible>>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for VarError

### impl Arbitrary for VarError

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<Just<VarError>>), (u32, Arc<Map<BoxedStrategy<OsString>, fn(_: <BoxedStrategy<OsString> as Strategy>::Value) -> VarError>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for SeekFrom

### impl Arbitrary for SeekFrom

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<Map<<u64 as Arbitrary>::Strategy, fn(_: u64) -> SeekFrom>>), (u32, Arc<Map<<i64 as Arbitrary>::Strategy, fn(_: i64) -> SeekFrom>>), (u32, Arc<Map<<i64 as Arbitrary>::Strategy, fn(_: i64) -> SeekFrom>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for ErrorKind

### impl Arbitrary for ErrorKind

#### type Parameters = ()

#### type Strategy = Union<Just<ErrorKind>>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for RecvTimeoutError

### impl Arbitrary for RecvTimeoutError

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<Just<RecvTimeoutError>>), (u32, Arc<Just<RecvTimeoutError>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for TryRecvError

### impl Arbitrary for TryRecvError

#### type Parameters = ()

#### type Strategy = TupleUnion<((u32, Arc<Just<TryRecvError>>), (u32, Arc<Just<TryRecvError>>))>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for bool

### impl Arbitrary for bool

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for char

### impl Arbitrary for char

#### type Parameters = ()

#### type Strategy = CharStrategy<'static>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for f32

### impl Arbitrary for f32

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for f64

### impl Arbitrary for f64

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for i8

### impl Arbitrary for i8

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for i16

### impl Arbitrary for i16

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for i32

### impl Arbitrary for i32

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for i64

### impl Arbitrary for i64

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for i128

### impl Arbitrary for i128

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for isize

### impl Arbitrary for isize

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for u8

### impl Arbitrary for u8

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for u16

### impl Arbitrary for u16

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for u32

### impl Arbitrary for u32

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for u64

### impl Arbitrary for u64

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for u128

### impl Arbitrary for u128

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for ()

### impl Arbitrary for ()

#### type Parameters = ()

#### type Strategy = Just<()>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for usize

### impl Arbitrary for usize

#### type Parameters = ()

#### type Strategy = Any

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for Box<str>

### impl Arbitrary for Box<str>

#### type Parameters = StringParam

#### type Strategy = MapInto<<String as Arbitrary>::Strategy, Box<str>>

#### fn arbitrary_with(a: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for Box<OsStr>

### impl Arbitrary for Box<OsStr>

#### type Parameters = <String as Arbitrary>::Parameters

#### type Strategy = MapInto<<OsString as Arbitrary>::Strategy, Box<OsStr>>

#### fn arbitrary_with(a: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for CString

### impl Arbitrary for CString

#### type Parameters = SizeRange

#### type Strategy = Map<VecStrategy<RangeInclusive<u8>>, fn(_: <VecStrategy<RangeInclusive<u8>> as Strategy>::Value) -> CString>

#### fn arbitrary_with(args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for IntoStringError

### impl Arbitrary for IntoStringError

#### type Parameters = ()

#### type Strategy = Map<BoxedStrategy<Vec<u8>>, fn(_: <BoxedStrategy<Vec<u8>> as Strategy>::Value) -> IntoStringError>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for Rc<str>

### impl Arbitrary for Rc<str>

#### type Parameters = StringParam

#### type Strategy = MapInto<<String as Arbitrary>::Strategy, Rc<str>>

#### fn arbitrary_with(a: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for FromUtf8Error

### impl Arbitrary for FromUtf8Error

#### type Parameters = ()

#### type Strategy = Map<BoxedStrategy<Vec<u8>>, fn(_: <BoxedStrategy<Vec<u8>> as Strategy>::Value) -> FromUtf8Error>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for FromUtf16Error

### impl Arbitrary for FromUtf16Error

#### type Parameters = ()

#### type Strategy = LazyJust<FromUtf16Error, fn() -> FromUtf16Error>

#### fn arbitrary_with(_args: Self::Parameters) -> Self::Strategy

source§### impl Arbitrary for String

### impl Arbitrary for String

source§#### fn arbitrary_with(args: Self::Parameters) -> Self::Strategy

#### fn arbitrary_with(args: Self::Parameters) -> Self::Strategy

###### §Panics

This implementation panics if the input is not a valid regex proptest can handle.