Macro field_mask 

macro_rules! field_mask {
    ($field:literal) => { ... };
    ($first:literal, $($rest:literal),+ $(,)?) => { ... };
}

Joins field names with commas to build a read mask string constant.

Accepts string literals only (for compile-time concatenation via concat!). To combine pre-defined constants at runtime, use field_masks_merge! instead.

Example

use iota_grpc_types::field_mask;

const MASK: &str = field_mask!("transaction.digest", "effects.bcs");
assert_eq!(MASK, "transaction.digest,effects.bcs");