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/// Implements 'From' for a list of variants, intended for use with error enums /// that are wrapping a number of errors from other methods. #[macro_export] macro_rules! impl_from { ( $enum_name: ident { $($error_type: ty => $variant_name: ident),* $(,)* } ) => { $( impl From<$error_type> for $enum_name { fn from(error: $error_type) -> $enum_name { $enum_name::$variant_name(error) } } )* } }