StringCreator

Assembling a string with a pre-known resulting string length: uses 50% less memory then StringBuilder.

Benchmark:

Method	StrLength	Mean	Ratio	Allocated	Alloc Ratio
StringBuilder	5	44.30 ns	1.00	120 B	1.00
Class.StringCreator	5	43.14 ns	0.97	64 B	0.53
StringBuilder	7	56.79 ns	1.00	128 B	1.00
Class.StringCreator	7	56.40 ns	0.99	72 B	0.56
StringBuilder	10	74.07 ns	1.00	144 B	1.00
Class.StringCreator	10	80.66 ns	1.09	80 B	0.56
StringBuilder	50	331.46 ns	1.00	304 B	1.00
Class.StringCreator	50	346.74 ns	1.05	160 B	0.53
StringBuilder	100	660.38 ns	1.00	496 B	1.00
Class.StringCreator	100	676.53 ns	1.02	256 B	0.52
StringBuilder	1000	6,695.47 ns	1.00	4096 B	1.00
Class.StringCreator	1000	6,649.87 ns	0.99	2056 B	0.50
StringBuilder	2500	16,218.35 ns	1.00	10096 B	1.00
Class.StringCreator	2500	16,578.15 ns	1.02	5056 B	0.50
StringBuilder	5000	32,402.59 ns	1.00	20096 B	1.00
Class.StringCreator	5000	33,884.77 ns	1.05	10056 B	0.50
StringBuilder	10000	64,693.92 ns	1.00	40096 B	1.00
Class.StringCreator	10000	66,447.20 ns	1.03	20056 B	0.50
StringBuilder	100000	748,646.58 ns	1.00	400138 B	1.00
Class.StringCreator	100000	707,204.32 ns	0.94	200077 B	0.50
StringBuilder	500000	3,720,999.90 ns	1.00	2000265 B	1.00
Class.StringCreator	500000	3,534,275.66 ns	0.95	1000141 B	0.50
StringBuilder	1071741	7,858,668.65 ns	1.00	4287176 B	1.00
Class.StringCreator	1071741	7,359,583.80 ns	0.94	2143628 B	0.50

Usage:

            var stringCreator = new StringCreator.Class.StringCreator(50);
            for (int i = 0; i < 50; i++)
            {
                stringCreator.Append($"{i % 10}");
            }

            var result = stringCreator.ToString();