Applicable on struct and enum definitions.

It derives traits necessary for encoding/decoding a custom type as revert error data.

The following traits are derived depending on the ABI mode:

• In "ink" and "all" ABI mode:
  • scale::Encode and scale::Decode for encoding/decoding ink! revert error data
  • scale_info::TypeInfo for generating ink! contract metadata (gated behind the std feature)
• In "sol" and "all" ABI mode:
  • SolErrorEncode and SolErrorDecode for encoding/decoding custom types as Solidity custom errors
  • SolErrorMetadata for generating Solidity ABI metadata (gated behind the std feature)

Example

#[ink::error]
struct UnitError;

#[ink::error]
enum MultipleErrors {
    UnitError,
    ErrorWithParams(bool, u8, String),
    ErrorWithNamedParams {
        status: bool,
        count: u8,
        reason: String,
    }
}

note

See our Solidity ABI compatibility docs for more details about handling Solidity ABI encoded revert error data.