Enum amplify_syn::ValueReq[][src]

pub enum ValueReq {
    Required,
    Default(ArgValue),
    Optional,
    Prohibited,
}

Requirements for attribute or named argument value presence for a values with known class. If the value class is not known, use ArgValueReq instead.

Variants

Required

Argument or an attribute must hold a value

Default(ArgValue)

Argument or an attribute must hold a value; if the value is not present it will be substituted for the default value provided as the inner field

Optional

Argument or an attribute may or may not hold a value

Prohibited

Argument or an attribute must not hold a value

Implementations

impl ValueReq[src]

pub fn is_required(&self) -> bool[src]

Detects if the presence of the value is required

pub fn check<T>(
    &self,
    value: &mut T,
    attr: impl ToString,
    arg: impl ToString
) -> Result<(), Error> where
    T: Clone + Into<ArgValue>,
    ArgValue: TryInto<T>,
    Error: From<<ArgValue as TryInto<T>>::Error>, 
[src]

Checks the value against current requirements, generating Error if the requirements are not met.

Trait Implementations

impl Clone for ValueReq[src]

Auto Trait Implementations

impl RefUnwindSafe for ValueReq

impl !Send for ValueReq

impl !Sync for ValueReq

impl Unpin for ValueReq

impl UnwindSafe for ValueReq

Blanket Implementations

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

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

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

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

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

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

type Owned = T

The resulting type after obtaining ownership.

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.

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.