Trait FromMeta

pub trait FromMeta: Sized {
    // Required method
    fn from_meta(meta: &MetaItem) -> Result<Self>;

    // Provided methods
    fn from_attr(attr: &Attribute) -> Result<Self> { ... }
    fn from_attrs(name: &str, attrs: &[Attribute]) -> Result<Vec<Self>> { ... }
    fn one_from_attrs(name: &str, attrs: &[Attribute]) -> Result<Option<Self>> { ... }
    fn default() -> Option<Self> { ... }
}

Required Methods

fn from_meta(meta: &MetaItem) -> Result<Self>

Provided Methods

fn from_attr(attr: &Attribute) -> Result<Self>

fn from_attrs(name: &str, attrs: &[Attribute]) -> Result<Vec<Self>>

fn one_from_attrs(name: &str, attrs: &[Attribute]) -> Result<Option<Self>>

fn default() -> Option<Self>

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl FromMeta for Expr

fn from_meta(meta: &MetaItem) -> Result<Self>

impl FromMeta for bool

fn from_meta(meta: &MetaItem) -> Result<Self>

impl FromMeta for isize

fn from_meta(meta: &MetaItem) -> Result<Self>

impl FromMeta for usize

fn from_meta(meta: &MetaItem) -> Result<Self>

impl FromMeta for TokenStream

fn from_meta(meta: &MetaItem) -> Result<Self>

impl FromMeta for String

fn from_meta(meta: &MetaItem) -> Result<Self>

impl<T: Parse, P: Parse> FromMeta for Punctuated<T, P>

fn from_meta(meta: &MetaItem) -> Result<Self>

impl<T: FromMeta> FromMeta for Option<T>

fn from_meta(meta: &MetaItem) -> Result<Self>

fn default() -> Option<Self>

Implementors

impl<T: FromMeta> FromMeta for SpanWrapped<T>