Macro config_field 

macro_rules! config_field {
    ($t:ty) => { ... };
    ($t:ty, $arg:ident => $transform:expr) => { ... };
}

Macro that generates ConfigField for a given type.

Usage

This always requires Display to be implemented for the given type.

There are two ways to invoke this macro. The first one uses default_config_transform/FromStr to parse the data:

config_field(MyType);

Note that the parsing error MUST implement std::error::Error!

Or you can specify how you want to parse an str into the type:

fn parse_it(s: &str) -> Result<MyType> {
    ...
}

config_field(
    MyType,
    value => parse_it(value)
);