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.