A ReadOnly StringSlice or string_view in C#.

because System.String.Substring will allocate new spaces and copy the chars, so StringView won't do this.

StringView only contains String's reference and the slice's begin and length property,

and many algorithm based on these three property.

there is not one complete benchmark between String and StringView, i will finish this in few days.

StringView supply:

• IndexOf
• IndexOfAny
• LastIndexOf
• LastIndexOfAny
• Contains
• StartsWith
• EndsWith
• Substring
• Split
• Concat
• Join