mixin StructParams!("S", int, "x", float, "y");
immutable S.WithDefaults combinedMain = { x: 12 }; // y is default-initialized
immutable S.Regular combinedDefault = { x: 11, y: 3.0 };
immutable combined = combine(combinedMain, combinedDefault);
assert(combined.x == 12 && combined.y == 3.0);Note that we cannot use struct literals like S.Regular(x: 11, y: 3.0) in the current version (v2.084.1) of D, just because current version of D does not have this feature. See DIP71.
Creates a "combined" structure from main and default_. The combined structure contains member values from main whenever !isNull for this value and otherwise values from default_.