Enum rustc_span::hygiene::Transparency [−][src]
pub enum Transparency {
Transparent,
SemiTransparent,
Opaque,
}
Expand description
A property of a macro expansion that determines how identifiers produced by that expansion are resolved.
Variants
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.
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.
Trait Implementations
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Auto Trait Implementations
impl RefUnwindSafe for Transparency
impl Send for Transparency
impl Sync for Transparency
impl Unpin for Transparency
impl UnwindSafe for Transparency
Blanket Implementations
Mutably borrows from an owned value. Read more
Layout
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.
Size: 1 byte
Size for each variant:
Transparent
: 0 bytesSemiTransparent
: 0 bytesOpaque
: 0 bytes