Enum 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 duplicate of the value.

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

Performs copy-assignment from source.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 264 bytes

Size for each variant:

• Required: 0 bytes
• Default: 264 bytes
• Optional: 0 bytes
• Prohibited: 0 bytes