pin-init/src/macros.rs

73 //! This macro is used to specify which fields are structurally pinned and which fields are not. It
74 //! is placed on the struct definition and allows `#[pin]` to be placed on the fields.
155 //!     // fields (those marked with `#[pin]`). These fields will be listed in this struct, in our
156 //!     // case no such fields exist, hence this is almost empty. The two phantomdata fields exist
225 //!             // Get the data about fields from the supplied type.
533 /// fields. Afterwards it declares the struct and implement the `PinData` trait safely.
548         @body({ $($fields:tt)* }),
550         // We now use token munching to iterate through all of the fields. While doing this we
551         // identify fields marked with `#[pin]`, these fields are the 'pinned fields'. The user
552         // wants these to be structurally pinned. The rest of the fields are the
553         // 'not pinned fields'. Additionally we collect all fields, since we need them in the right
575             // The remaining fields tokens that need to be processed.
577             @fields_munch($($fields)* ,),
578             // The pinned fields.
580             // The not pinned fields.
582             // All fields.
583             @fields(),
604         @fields($($fields:tt)*),
626             @fields($($fields)* $($accum)* $field: ::core::marker::PhantomPinned,),
644         @fields($($fields:tt)*),
661             @fields($($fields)* $($accum)* $field: $type,),
679         @fields($($fields:tt)*),
696             @fields($($fields)* $($accum)* $field: $type,),
714         @fields($($fields:tt)*),
732             @fields($($fields)*),
752         @fields($($fields:tt)*),
768             @fields($($fields)*),
786         @fields($($fields:tt)*),
802             @fields($($fields)*),
816         // We reached the end of the fields, plus an optional additional comma, since we added one
821         @fields($($fields:tt)*),
826         // Declare the struct with all fields in the correct order.
831             $($fields)*
890             // fields are relevant whether the struct should implement `Unpin`.
899                 // Only the pinned fields.
1034 /// - `init_slot`: recursively creates the code that initializes all fields in `slot`.
1043         @fields($($fields:tt)*),
1057             @fields($($fields)*),
1068         @fields($($fields:tt)*),
1082             @fields($($fields)*),
1087             @zeroed(()), // `()` means zero all fields not mentioned.
1093         @fields($($fields:tt)*),
1107             @fields($($fields)*),
1118         @fields($($fields:tt)*),
1133         // Get the data about fields from the supplied type.
1152                     // error when fields are missing (since they will be zeroed). We also have to
1163                     // expressions creating the individual fields.
1170                         @munch_fields($($fields)*,),
1172                     // We use unreachable code to ensure that all fields have been mentioned exactly
1180                             @munch_fields($($fields)*,),
1201         // Endpoint of munching, no fields are left. If execution reaches this point, all fields
1205     (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields.
1308         // not been overwritten are thus zero and initialized. We still check that all fields are