Struct HookArgs

#[non_exhaustive]
pub struct HookArgs {
    pub hooks_core_path: Option<PathOrLit<Path>>,
    pub bounds: Option<Punctuated<TypeParamBound, Plus>>,
}

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

hooks_core_path: Option<PathOrLit<Path>>

Defaults to ::hooks::core

bounds: Option<Punctuated<TypeParamBound, Plus>>

When a hook fn borrows from a lifetime, this bound might need to be explicitly specified.

Note that all lifetimes declared in fn generics are auto captured by #[hook]. Thus, #[hook(bounds = "...")] is only required for elided lifetimes and outer lifetimes.

#[hook]
fn use_borrow(v: &str) -> usize {
    v.len()
}

#[hook(bounds = "'_")]
fn use_borrow(v: &str) -> usize {
    v.len()
}

This is equivalent to type Bounds = impl ... in hook_fn!(...);

hook_fn!(
    type Bounds = impl '_;
    fn use_borrow(v: &str) -> usize {
        v.len()
    }
);

Implementations

impl HookArgs

pub fn transform_item_fn(self, item_fn: ItemFn) -> (ItemFn, Option<Error>)

pub fn transform_item_fn_in_place(self, item_fn: &mut ItemFn) -> Option<Error>

pub fn from_punctuated_meta_list( meta_list: Punctuated<NestedMeta, Comma>, ) -> Result<Self>

Trait Implementations

impl Debug for HookArgs

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for HookArgs

fn default() -> HookArgs

Returns the “default value” for a type.

impl FromMeta for HookArgs

fn from_list(__items: &[NestedMeta]) -> Result<Self>

Create an instance from a list of nested meta items.

fn from_nested_meta(item: &NestedMeta) -> Result<Self, Error>

fn from_meta(item: &Meta) -> Result<Self, Error>

Create an instance from a syn::Meta by dispatching to the format-appropriate trait function. This generally should not be overridden by implementers.

fn from_none() -> Option<Self>

When a field is omitted from a parent meta-item, from_none is used to attempt recovery before a missing field error is generated.

fn from_word() -> Result<Self, Error>

Create an instance from the presence of the word in the attribute with no additional options specified.

fn from_value(value: &Lit) -> Result<Self, Error>

Create an instance from a literal value of either foo = "bar" or foo("bar"). This dispatches to the appropriate method based on the type of literal encountered, and generally should not be overridden by implementers.

fn from_expr(expr: &Expr) -> Result<Self, Error>

fn from_char(value: char) -> Result<Self, Error>

Create an instance from a char literal in a value position.

fn from_string(value: &str) -> Result<Self, Error>

Create an instance from a string literal in a value position.

fn from_bool(value: bool) -> Result<Self, Error>

Create an instance from a bool literal in a value position.