Derive Macro clap_derive::Parser

#[derive(Parser)]
{
    // Attributes available to this derive:
    #[clap]
    #[structopt]
}

Generates the Parser implementation.

This is far less verbose than defining the clap::App struct manually, receiving an instance of clap::ArgMatches from conducting parsing, and then implementing a conversion code to instantiate an instance of the user context struct.