Fast & Non-Alloc String Builder for Unity

Runtime/Text/UString.cs   HeaderDoc

(c) 2024 Sator Imaging, Licensed under the MIT License https://github.com/sator-imaging/Unity-Fundamentals

One liner API designed to easily achieve fast & allocation-free string operation.

// basic usage
var text = UString.Concat("Value: ", intVal);
var text = UString.Concat("Value: ", intVal.ToCharSpan("D5"));
//                                         ~~~~~~~~~~~~~~~~~ instant non-alloc formatter

// 'using' statement is required to use as StringBuilder alternative
using (var sb = UString.Rent())
{
    sb.Append("Value: ");
    sb.Append(intValue);

    UString.NewLineChars = "\r\n";
    sb.NewLine();

    var (array, consumed) = sb.GetRawBuffer();
    textMeshPro.SetCharArray(array, 0, consumed);
}

Technical Notes

Prevent Allocation on Formatting Enum Types

Install StrictEnum and set preprocessor symbol STMG_USTRING_USE_STRICT_ENUM. (on Unity, symbol is automatically set)

Note that in .NET 8 or later version, StrictEnum is not required.

Overriding Formatter

There is an ability to override formatter by setting Override***Formatter.

Formatter Precedence for Non-Primitive Types

UString chooses applicable formatter in the following order.

• Enum
• IFormattable
• Nullable<T>
• ValueType
• Object