PropertyMacroFn

Type Alias PropertyMacroFn 

Source
pub type PropertyMacroFn<D> = fn(&D, TokenStream) -> Result<TokenStream, Error>;
Expand description

Type of function that computes a property macro result.

The function is called with a reference to custom input data and the token stream it is called with. It should return a token stream it will be replaced with or alternatively an error.

For example, a macro with name example can be called within properties as example!(example_data). The input token stream will then contain example_data. The macro can then return example_result and will be replaced by this result before further processing. Alternatively, it can return an error, which will result in property verification failure.