Enum amplify_syn::ValueReq

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

pub fn is_required(&self) -> bool

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,
    ArgValue: From<T> + TryInto<T>,
    Error: From<<ArgValue as TryInto<T>>::Error>, 

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

Trait Implementations

impl Clone for ValueReq

fn clone(&self) -> ValueReq

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.