Decimal.sameQuantum

bool sameQuantum(
          const  typeof(
          this)  rhs)

const @safe pure nothrow @nogc

IEEE sameQuantum: true when both operands are finite with the same stored exponent, both are infinities (either sign), or both are NaNs of any kind — payloads and signs do not matter. Exactly one NaN operand gives false. Never signals.