Trait gdnative_core::core_types::ToVariant
source · pub trait ToVariant {
fn to_variant(&self) -> Variant;
}Expand description
Types that can be converted to a Variant.
Wrappers and collections
Implementations are provided for a few common Rust wrappers and collections:
Option<T>is unwrapped to inner value, orNilifNoneResult<T, E>is represented as an externally taggedDictionary(see below).PhantomData<T>is represented asNil.&[T]andVec<T>are represented asVariantArrays.FromVariantis only implemented forVec<T>.
Deriving ToVariant
The derive macro does the following mapping between Rust structures and Godot types:
Newtype(inner)is unwrapped toinnerTuple(a, b, c)is represented as aVariantArray([a, b, c])Struct { a, b, c }is represented as aDictionary({ "a": a, "b": b, "c": c })Unitis represented as an emptyDictionary({})Enum::Variant(a, b, c)is represented as an externally taggedDictionary({ "Variant": [a, b, c] }), unless another representation is specified with#[variant(enum)](see below).
Behavior of the derive macros can be customized using attributes:
Item attributes
#[variant(enum = "str")]
Only applicable to field-less enums. Variants of types annotated with this attribute
are represented as stringified values of their names, i.e. "Variant" for Enum::Variant.
#[variant(enum = "repr")]
Only applicable to field-less enums with a explicit primitive #[repr] type. Variants of
types annotated with this attribute are represented as their primitive integral values.
Field attributes
#[variant(to_variant_with = "path::to::func")]
Use the given function to convert the field to Variant. The function’s signature is
expected to be fn(&T) -> Variant, although it can be generic over T.
#[variant(from_variant_with = "path::to::func")]
Use the given function to convert from a Variant. The function’s signature is
expected to be fn(&Variant) -> Result<T, FromVariantError>, although it can be generic
over T.
#[variant(with = "path::to::mod")]
Convenience attribute that sets to_variant_with to path::to::mod::to_variant and
from_variant_with to path::to::mod::from_variant.
#[variant(skip_to_variant)]
Skip the field when converting to Variant.
#[variant(skip_from_variant)]
Skip the field when converting from Variant. A default vale will be obtained using
Default::default().
#[variant(skip)]
Convenience attribute that sets skip_to_variant and skip_from_variant.
Required Methods§
fn to_variant(&self) -> Variant
Implementations on Foreign Types§
source§impl<'a, T> ToVariant for &'a Twhere
T: ToVariant + ?Sized,
impl<'a, T> ToVariant for &'a Twhere
T: ToVariant + ?Sized,
fn to_variant(&self) -> Variant
source§impl<'a, T> ToVariant for &'a mut Twhere
T: ToVariant + ?Sized,
impl<'a, T> ToVariant for &'a mut Twhere
T: ToVariant + ?Sized,
fn to_variant(&self) -> Variant
source§impl<T> ToVariant for PhantomData<T>
impl<T> ToVariant for PhantomData<T>
fn to_variant(&self) -> Variant
source§impl<T: ToVariant, E: ToVariant> ToVariant for Result<T, E>
impl<T: ToVariant, E: ToVariant> ToVariant for Result<T, E>
fn to_variant(&self) -> Variant
source§impl<K: ToVariant + Hash + ToVariantEq, V: ToVariant> ToVariant for HashMap<K, V>
impl<K: ToVariant + Hash + ToVariantEq, V: ToVariant> ToVariant for HashMap<K, V>
Converts the hash map to a Dictionary, wrapped in a Variant.
Note that Rust’s HashMap is non-deterministically ordered for security reasons, meaning that
the order of the same elements will differ between two program invocations. To provide a
deterministic output in Godot (e.g. UI elements for properties), the elements are sorted by key.
fn to_variant(&self) -> Variant
source§impl<T: ToVariant> ToVariant for HashSet<T>
impl<T: ToVariant> ToVariant for HashSet<T>
Converts the hash set to a VariantArray, wrapped in a Variant.
Note that Rust’s HashSet is non-deterministically ordered for security reasons, meaning that
the order of the same elements will differ between two program invocations. To provide a
deterministic output in Godot (e.g. UI elements for properties), the elements are sorted by key.