macro_tools 0.85.0

//!
//! Property of an attribute which simply wraps one of the standard `syn` types and keeps it optional.
//!
use core ::marker ::PhantomData;

use crate :: *;
// use component_model_types ::Assign;

/// Default marker for `AttributePropertyOptionalSyn`.
/// Used if no marker is defined as parameter.
#[ derive( Debug, Default, Clone, Copy ) ]
pub struct AttributePropertyOptionalSynMarker;

///
/// Property of an attribute which simply wraps one of the standard `syn` types and keeps it optional.
///
#[ derive( Debug, Clone ) ]
pub struct AttributePropertyOptionalSyn< T, Marker = AttributePropertyOptionalSynMarker >(
  Option< T >,
  ::core ::marker ::PhantomData< Marker >,
)
where
  T: syn ::parse ::Parse + quote ::ToTokens;

impl< T, Marker > AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  /// Just unwraps and returns the internal data.
  #[ inline( always ) ]
  pub fn internal(self) -> Option< T >
  {
  self.0
 }

  /// Returns an Option reference to the internal data.
  #[ inline( always ) ]
  pub fn ref_internal( &self ) -> Option< &T >
  {
  self.0.as_ref()
 }
}

impl< T, Marker, IntoT > Assign< AttributePropertyOptionalSyn<T, Marker >, IntoT> for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
  IntoT: Into< AttributePropertyOptionalSyn<T, Marker >>,
{
  /// Inserts value of another instance into the option if it is None, then returns a mutable reference to the contained value.
  /// If another instance does is None then do nothing.
  #[ allow( clippy ::single_match ) ]
  #[ inline( always ) ]
  fn assign(&mut self, component: IntoT) 
  {
  let component = component.into();
  match component.0 
  {
   Some(val) =>
  {
  self.0 = Some(val);
 }
   None => {}
 }
 }
}

impl< T, Marker > AttributePropertyComponent for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
  Marker: AttributePropertyComponent,
{
  const KEYWORD: &'static str = Marker ::KEYWORD;
}

impl< T, Marker > Default for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ allow( clippy ::default_constructed_unit_structs ) ]
  fn default() -> Self 
  {
  Self(None, PhantomData ::default())
 }
}

impl< T, Marker > syn ::parse ::Parse for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  fn parse(input: syn ::parse ::ParseStream< '_ >) -> syn ::Result< Self > 
  {
  input.parse :: < syn ::Token![ = ] >()?;
  let value: T = input.parse()?;
  Ok(value.into())
 }
}

impl< T, Marker > quote ::ToTokens for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  fn to_tokens(&self, tokens: &mut proc_macro2 ::TokenStream) 
  {
  self.0.to_tokens(tokens);
 }
}

impl< T, Marker > core ::ops ::Deref for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  type Target = Option< T >;
  #[ inline( always ) ]
  fn deref( &self ) -> &Option< T > 
  {
  &self.0
 }
}

impl< T, Marker > AsRef< Option< T >> for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ inline( always ) ]
  fn as_ref( &self ) -> &Option< T > 
  {
  &self.0
 }
}

impl< T, Marker > From< T > for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ inline( always ) ]
  #[ allow( clippy ::default_constructed_unit_structs ) ]
  fn from(src: T) -> Self 
  {
  Self(Some(src), PhantomData ::default())
 }
}

impl< T, Marker > From< Option< T >> for AttributePropertyOptionalSyn< T, Marker >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ inline( always ) ]
  #[ allow( clippy ::default_constructed_unit_structs ) ]
  fn from(src: Option< T >) -> Self 
  {
  Self(src, PhantomData ::default())
 }
}

impl< T, Marker > From< AttributePropertyOptionalSyn<T, Marker >> for Option< T >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ inline( always ) ]
  fn from(src: AttributePropertyOptionalSyn< T, Marker >) -> Self 
  {
  src.0
 }
}

impl< 'a, T, Marker > From< &'a AttributePropertyOptionalSyn<T, Marker >> for Option< &'a T >
where
  T: syn ::parse ::Parse + quote ::ToTokens,
{
  #[ inline( always ) ]
  fn from(src: &'a AttributePropertyOptionalSyn< T, Marker >) -> Self 
  {
  src.0.as_ref()
 }
}