Enum EnvBinding 

pub enum EnvBinding {
    None,
    Standard,
    Overridden(Vec<String>),
}

How a config field is reachable through an environment variable.

Mirrors the Datadog Agent’s bindEnv: a setting either has no env var, uses the standard DD_ + UPPER(dotted_path) name derived from its key, or declares explicit names that replace that derived default. The distinction matters to codegen: the standard name is computable from the path, an overridden name is not, and a field with no env var must never be treated as env-reachable.

Variants

None

The field carries a no-env tag: no environment variable maps to it.

Standard

No explicit env vars are declared, so the Agent derives DD_ + UPPER(dotted_path).

Overridden(Vec<String>)

The schema declares explicit environment variable names, which replace the derived default. Non-empty.