Function decrement Copy item path

Decrements and returns the new value stored by the given environment variable key. In case the variable does not exist, it will decrement to -1. The updated value will be returned.

§Arguments

• key - The environment variable name

§Example

fn main() {
    envmnt::set_u8("ENV_VAR", 5);
    let value = envmnt::decrement("ENV_VAR");
    assert_eq!(value, 4);
}