Enum InvocationContext

pub enum InvocationContext {
    Expr,
    Item,
    Pat,
    Stmt,
    Ty,
}

The contexts in which a macro can be called.

All macros can’t be called in all contexts. For instance, a macro that expands to a pattern may not be called where an expression is expected. This type allows the check_macro function to know the context the macro will be invoked in.

Variants

Expr

The macro expands to an expression.

Item

The macro expands to any number of item.

Pat

The macro expands to a pattern.

Stmt

The macro expands to any number of statement.

Ty

The macro expands to a type.

Trait Implementations

impl Clone for InvocationContext

fn clone(&self) -> InvocationContext

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for InvocationContext

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

Formats the value using the given formatter.

impl FromStr for InvocationContext

type Err = ()

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<InvocationContext, ()>

Parses a string s to return a value of this type.

impl PartialEq for InvocationContext

fn eq(&self, other: &InvocationContext) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for InvocationContext

impl StructuralPartialEq for InvocationContext