How to use a float as an env var in cargo/rust? - rust

Question

Like the title suggests, how can I create an env variable in cargo that is of type float?
I have a created .cargo/config.toml file and would like to add all the game related env variables like so:
[env]
test = "testtingggg"
yo = "yoyoyoyoyoyo"
game_zero_level = "hello"
game_zero_multiplier = 0.1
# game_one_level = 1
# game_one_multiplier = 1.0
# game_two_level = 2
# game_two_multiplier = 2.5
# game_three_level = 3
# game_three_multiplier = 5.0
# game_four_level = 3
#[derive(Serialize, Deserialize, Debug)]
pub struct Config {
pub level_zero: LevelZero,
pub level_one: LevelOne,
pub level_two: LevelTwo,
pub level_three: LevelThree,
pub level_four: LevelFour,
}
impl Config {
pub fn new() -> Self {
// Get env variables
let temp = option_env!("game_zero_level").unwrap();
msg!("simple env read for first game...");
msg!("{}", temp);
// load them into struct
// template for now
Config {
level_zero: LevelZero { level: 0, multiplier: 1.0 },
level_one: LevelOne { level: 1, multiplier: 1.0 },
level_two: LevelTwo { level: 2, multiplier: 1.0 },
level_three: LevelThree { level: 3, multiplier: 1.0 },
level_four: LevelFour { level: 4, multiplier: 1.0 },
}
}
}
Code
However, I got an error:
2022-12-24T18:22:59.802122509Z ERROR cargo_build_sbf] Failed to obtain packag
e metadata: `cargo metadata` exited with an error: error: could not load Cargo
configuration
Caused by:
failed to load TOML configuration from `/home/tai/Code/solana/techniques
/env-vars3/programs/env-vars3/.cargo/config.toml`
Caused by:
failed to parse key `env`
Caused by:
failed to parse key `game_zero_multiplier`
Caused by:
found TOML configuration value of unknown type `float`
error
Any suggestions would be soo appreciated! Thanks