macro_rules! prod_or_testnet_or_local { ($prod:expr, $test:expr, $local:expr) => { ... }; }
Expand description
Macro to set a value (e.g. when using the parameter_types
macro) to either a production value
or to an environment variable or testing value (in case the frequency-local
feature is selected or in instant sealing mode).
Note that the environment variable is evaluated at compile time.
Usage:
parameter_types! {
// Note that the env variable version parameter cannot be const.
pub LaunchPeriod: BlockNumber = prod_or_testnet_or_local!(7 * DAYS, 28 * DAYS, 1 * MINUTES);
pub const VotingPeriod: BlockNumber = prod_or_testnet_or_local!(7 * DAYS, 28 * DAYS, 1 * MINUTES);
}