pub(crate) trait SetOnce<T> {
// Required methods
fn set_once(&mut self, value: T, span: Span);
fn value(self) -> Option<T>;
fn value_ref(&self) -> Option<&T>;
}Expand description
Small helper trait for abstracting over Option fields that contain a value and a Span
for error reporting if they are set more than once.
Required Methods§
fn set_once(&mut self, value: T, span: Span)
fn value(self) -> Option<T>
fn value_ref(&self) -> Option<&T>
Dyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".