Decimal.remainder

typeof(this) remainder(
          const  typeof(
          this)  rhs,  ref  DecimalContext ctx)

const @safe pure nothrow @nogc

IEEE remainder: this - n * rhs with n the truncated integer quotient (fmod semantics; the sign follows this). Exact (no rounding flags); the result keeps the ideal exponent of the reduction and reports Clamped when storage pads it, Subnormal when tiny. rhs == 0 or an infinite operand signals INVALID_OPERATION (NaN result).