Decimal.reduce

typeof(this) reduce(ref DecimalContext ctx) const @safe pure nothrow @nogc

The value with trailing coefficient zeros removed (decNumber reduce): 1.00 → 1, 10.0 → 1E+1; zeros keep their sign and collapse to exponent 0; specials return unchanged except that signaling NaNs quieten with INVALID_OPERATION. Never rounds, never sets other flags.