[−][src]Struct value_bag::ValueBag

pub struct ValueBag<'v> { /* fields omitted */ }

A dynamic structured value.

Capturing values

There are a few ways to capture a value:

Using the ValueBag::capture_* methods.
Using the standard From trait.
Using the Fill API.

Using the `ValueBag::capture_*` methods

ValueBag offers a few constructor methods that capture values of different kinds. These methods require a T: 'static to support downcasting.

use value_bag::ValueBag;

let value = ValueBag::capture_debug(&42i32);

assert_eq!(Some(42), value.to_i32());

Using the standard `From` trait

Standard types that implement ToValue also implement From.

use value_bag::ValueBag;

let value = ValueBag::from(42i32);

assert_eq!(Some(42), value.to_i32());

use value_bag::ValueBag;

let value = ValueBag::from(&42i32 as &dyn Debug);

assert_eq!(None, value.to_i32());

Using the `Fill` API

The Fill trait is a way to bridge APIs that may not be directly compatible with other constructor methods.

use value_bag::{ValueBag, Slot, Fill, Error};

struct FillSigned;

impl Fill for FillSigned {
    fn fill(&self, slot: &mut Slot) -> Result<(), Error> {
        slot.fill_any(42i32)
    }
}

let value = ValueBag::from_fill(&FillSigned);

assert_eq!(Some(42), value.to_i32());

use value_bag::{ValueBag, Slot, Fill, Error};

struct FillDebug;

impl Fill for FillDebug {
    fn fill(&self, slot: &mut Slot) -> Result<(), Error> {
        slot.fill_debug(&42i32 as &dyn Debug)
    }
}

let value = ValueBag::from_fill(&FillDebug);

assert_eq!(None, value.to_i32());

Inspecting values

Once you have a ValueBag there are also a few ways to inspect it:

Using the Debug, Display, Serialize, and Stream trait implementations.
Using the ValueBag::to_* methods.
Using the ValueBag::downcast_ref method.

Implementations

`impl<'v> ValueBag<'v>`[src]

`pub fn from_fill<T>(value: &'v T) -> Self where T: Fill,` [src]

Get a value from a fillable slot.

`impl<'v> ValueBag<'v>`[src]

`pub fn to_str(&self) -> Option<Cow<'_, str>>`[src]

Try get a str from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones. If the serialization implementation produces a short lived string it will be allocated.

`impl<'v> ValueBag<'v>`[src]

`pub fn to_usize(&self) -> Option<usize>`[src]

Try get a usize from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_u8(&self) -> Option<u8>`[src]

Try get a u8 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_u16(&self) -> Option<u16>`[src]

Try get a u16 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_u32(&self) -> Option<u32>`[src]

Try get a u32 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_u64(&self) -> Option<u64>`[src]

Try get a u64 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_isize(&self) -> Option<isize>`[src]

Try get a isize from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_i8(&self) -> Option<i8>`[src]

Try get a i8 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_i16(&self) -> Option<i16>`[src]

Try get a i16 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_i32(&self) -> Option<i32>`[src]

Try get a i32 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_i64(&self) -> Option<i64>`[src]

Try get a i64 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_f32(&self) -> Option<f32>`[src]

Try get a f32 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_f64(&self) -> Option<f64>`[src]

Try get a f64 from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_bool(&self) -> Option<bool>`[src]

Try get a bool from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_char(&self) -> Option<char>`[src]

Try get a char from this value.

This method is cheap for primitive types, but may call arbitrary serialization implementations for complex ones.

`pub fn to_borrowed_str(&self) -> Option<&str>`[src]

Try get a str from this value.

This method is cheap for primitive types. It won't allocate an owned String if the value is a complex type.

`pub fn is<T: 'static>(&self) -> bool`[src]

Check whether this value can be downcast to T.

`pub fn downcast_ref<T: 'static>(&self) -> Option<&T>`[src]

Try downcast this value to T.

`impl<'v> ValueBag<'v>`[src]

`pub fn capture_error<T>(value: &'v T) -> Self where T: Error + 'static,` [src]

Get a value from an error.

`pub fn to_error<'a>(&'a self) -> Option<impl Error + 'a>`[src]

Try get an error from this value.

`impl<'v> ValueBag<'v>`[src]

`pub fn capture_debug<T>(value: &'v T) -> Self where T: Debug + 'static,` [src]

Get a value from a debuggable type.

This method will attempt to capture the given value as a well-known primitive before resorting to using its Debug implementation.

`pub fn capture_display<T>(value: &'v T) -> Self where T: Display + 'static,` [src]

Get a value from a displayable type.

This method will attempt to capture the given value as a well-known primitive before resorting to using its Display implementation.

`impl<'v> ValueBag<'v>`[src]

`pub fn capture_serde<T>(value: &'v T) -> Self where T: Serialize + 'static,` [src]

Get a value from a structured type.

This method will attempt to capture the given value as a well-known primitive before resorting to using its Value implementation.

`impl<'v> ValueBag<'v>`[src]

`pub fn capture_sval<T>(value: &'v T) -> Self where T: Value + 'static,` [src]

Get a value from a structured type.

This method will attempt to capture the given value as a well-known primitive before resorting to using its Value implementation.

Trait Implementations

`impl<'v> Clone for ValueBag<'v>`[src]

`fn clone(&self) -> ValueBag<'v>`[src]

`fn clone_from(&mut self, source: &Self)`1.0.0[src]

`impl<'v> Debug for ValueBag<'v>`[src]

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

`impl<'v> Display for ValueBag<'v>`[src]

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

`impl<'v> From<&'v (dyn Debug + 'v)> for ValueBag<'v>`[src]

`fn from(value: &'v dyn Debug) -> ValueBag<'v>`[src]

`impl<'v> From<&'v (dyn Display + 'v)> for ValueBag<'v>`[src]

`fn from(value: &'v dyn Display) -> ValueBag<'v>`[src]

`impl<'v> From<&'v (dyn Error + 'v)> for ValueBag<'v>`[src]

`fn from(value: &'v dyn Error) -> ValueBag<'v>`[src]

`impl<'v> From<&'v (dyn Serialize + 'v)> for ValueBag<'v>`[src]

`fn from(value: &'v dyn Serialize) -> ValueBag<'v>`[src]

`impl<'v> From<&'v (dyn Value + 'v)> for ValueBag<'v>`[src]

`fn from(value: &'v dyn Value) -> ValueBag<'v>`[src]

`impl<'v> From<&'v str> for ValueBag<'v>`[src]

`fn from(value: &'v str) -> Self`[src]

`impl<'v> From<()> for ValueBag<'v>`[src]

`fn from(value: ()) -> Self`[src]

`impl<'v> From<bool> for ValueBag<'v>`[src]

`fn from(value: bool) -> Self`[src]

`impl<'v> From<char> for ValueBag<'v>`[src]

`fn from(value: char) -> Self`[src]

`impl<'v> From<f32> for ValueBag<'v>`[src]

`fn from(value: f32) -> Self`[src]

`impl<'v> From<f64> for ValueBag<'v>`[src]

`fn from(value: f64) -> Self`[src]

`impl<'v> From<i16> for ValueBag<'v>`[src]

`fn from(value: i16) -> Self`[src]

`impl<'v> From<i32> for ValueBag<'v>`[src]

`fn from(value: i32) -> Self`[src]

`impl<'v> From<i64> for ValueBag<'v>`[src]

`fn from(value: i64) -> Self`[src]

`impl<'v> From<i8> for ValueBag<'v>`[src]

`fn from(value: i8) -> Self`[src]

`impl<'v> From<isize> for ValueBag<'v>`[src]

`fn from(value: isize) -> Self`[src]

`impl<'v> From<u16> for ValueBag<'v>`[src]

`fn from(value: u16) -> Self`[src]

`impl<'v> From<u32> for ValueBag<'v>`[src]

`fn from(value: u32) -> Self`[src]

`impl<'v> From<u64> for ValueBag<'v>`[src]

`fn from(value: u64) -> Self`[src]

`impl<'v> From<u8> for ValueBag<'v>`[src]

`fn from(value: u8) -> Self`[src]

`impl<'v> From<usize> for ValueBag<'v>`[src]

`fn from(value: usize) -> Self`[src]

`impl<'v> Serialize for ValueBag<'v>`[src]

`fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error> where S: Serializer,` [src]

`impl<'v> Value for ValueBag<'v>`[src]

`fn stream(&self, s: &mut Stream<'_>) -> Result`[src]

Auto Trait Implementations

`impl<'v> !RefUnwindSafe for ValueBag<'v>`

`impl<'v> !Send for ValueBag<'v>`

`impl<'v> !Sync for ValueBag<'v>`

`impl<'v> Unpin for ValueBag<'v>`

`impl<'v> !UnwindSafe for ValueBag<'v>`

Blanket Implementations

`impl<T> Any for T where T: 'static + ?Sized,` [src]

`fn type_id(&self) -> TypeId`[src]

`impl<T> Borrow<T> for T where T: ?Sized,` [src]

`fn borrow(&self) -> &T`[src]

`impl<T> BorrowMut<T> for T where T: ?Sized,` [src]

`fn borrow_mut(&mut self) -> &mut T`[src]

`impl<T> From<T> for T`[src]

`fn from(t: T) -> T`[src]

`impl<T, U> Into<U> for T where U: From<T>,` [src]

`fn into(self) -> U`[src]

`impl<T> Serialize for T where T: Serialize + ?Sized,` [src]

`fn erased_serialize(&self, serializer: &mut dyn Serializer) -> Result<Ok, Error>`[src]

`impl<T> ToOwned for T where T: Clone,` [src]

`type Owned = T`

The resulting type after obtaining ownership.

`fn to_owned(&self) -> T`[src]

`fn clone_into(&self, target: &mut T)`[src]

`impl<T> ToString for T where T: Display + ?Sized,` [src]

`default fn to_string(&self) -> String`[src]

`impl<T, U> TryFrom<U> for T where U: Into<T>,` [src]

`type Error = Infallible`

The type returned in the event of a conversion error.

`fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

`impl<T, U> TryInto<U> for T where U: TryFrom<T>,` [src]

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

The type returned in the event of a conversion error.

`fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]