Enumap.opApply - multiple declarations

Prototype

int opApply(
  scope int delegate(K, const V) dg
) const;

Example

foreach iterates over (EnumMember, value) pairs.

const auto elements = enumap(Element.water, 4, Element.air, 3);

foreach(key, value ; elements) {
  assert(
      key == Element.water && value == 4 ||
      key == Element.air   && value == 3 ||
      value == 0);
}

Prototype

int opApply(
  scope int delegate(K, ref V) dg
);

Example

foreach can modify values by ref

Enumap!(Element, int) elements;

foreach(key, ref value ; elements) {
  if      (key == Element.air)   value = 4;
  else if (key == Element.water) value = 2;
}

assert(elements.air   == 4);
assert(elements.water == 2);