pub enum Transparency {
Transparent,
SemiTransparent,
Opaque,
}
A property of a macro expansion that determines how identifiers
produced by that expansion are resolved.
Identifier produced by a transparent expansion is always resolved at call-site.
Call-site spans in procedural macros, hygiene opt-out in macro
should use this.
(Not used yet.)
Identifier produced by a semi-transparent expansion may be resolved
either at call-site or at definition-site.
If it's a local variable, label or $crate
then it's resolved at def-site.
Otherwise it's resolved at call-site.
macro_rules
macros behave like this, built-in macros currently behave like this too,
but that's an implementation detail.
Identifier produced by an opaque expansion is always resolved at definition-site.
Def-site spans in procedural macros, identifiers from macro
by default use this.
Performs copy-assignment from source
. Read more
This method tests for self
and other
values to be equal, and is used by ==
. Read more
This method tests for !=
.
Formats the value using the given formatter. Read more