Amount.opOpAssign - multiple declarations

Function Amount.opOpAssign

Convenience version of add which throws in case of overflow Prefer using this only in unittests

ref Amount opOpAssign(string op : "+") (
  in Amount other
) @safe;

Function Amount.opOpAssign

Convenience version of sub which asserts in case of underflow Prefer using this only in unittests

ref Amount opOpAssign(string op : "-") (
  in Amount other
) @safe;