[−][src]Macro sp_phragmen_compact::generate_compact_solution_type

generate_compact_solution_type!() { /* proc-macro */ }

Generates a struct to store the phragmen assignments in a compact way. The struct can only store distributions up to the given input count. The given count must be greater than 2.

ⓘThis example is not tested
// generate a struct with nominator and edge weight u128, with maximum supported
// edge per voter of 16.
generate_compact_solution_type(pub TestCompact, 16)

This generates:

ⓘThis example is not tested
pub struct TestCompact<V, T, W> {
	votes1: Vec<(V, T)>,
	votes2: Vec<(V, (T, W), T)>,
	votes3: Vec<(V, [(T, W); 2usize], T)>,
	votes4: Vec<(V, [(T, W); 3usize], T)>,
	votes5: Vec<(V, [(T, W); 4usize], T)>,
	votes6: Vec<(V, [(T, W); 5usize], T)>,
	votes7: Vec<(V, [(T, W); 6usize], T)>,
	votes8: Vec<(V, [(T, W); 7usize], T)>,
	votes9: Vec<(V, [(T, W); 8usize], T)>,
	votes10: Vec<(V, [(T, W); 9usize], T)>,
	votes11: Vec<(V, [(T, W); 10usize], T)>,
	votes12: Vec<(V, [(T, W); 11usize], T)>,
	votes13: Vec<(V, [(T, W); 12usize], T)>,
	votes14: Vec<(V, [(T, W); 13usize], T)>,
	votes15: Vec<(V, [(T, W); 14usize], T)>,
	votes16: Vec<(V, [(T, W); 15usize], T)>,
}

The generic arguments are:

  • V: identifier/index for voter (nominator) types.
  • T identifier/index for candidate (validator) types.
  • W weight type.

Some conversion implementations are provided by default if

  • W is u128, or
  • W is anything that implements PerThing (such as Perbill)

The ideas behind the structure are as follows:

  • For single distribution, no weight is stored. The weight is known to be 100%.
  • For all the rest, the weight if the last distribution is omitted. This value can be computed from the rest.