envopt

Parse environment variables by defining a struct.

Example

```rust use envopt::EnvOpt;

[derive(EnvOpt)]

pub enum EnvOpts { #[envopt(name = "FOO")] Foo, #[envopt(name = "BAR", default = "default-bar")] Bar, }

pub fn main() { EnvOpts::validateorexit();

println!("FOO: {}", EnvOpts::Foo.value_or_exit());
println!("BAR: {}", EnvOpts::Bar.value_or_exit());

} ```