danyray420 / fastgenericnew

The ultimate fast alternative to Activator.CreateInstance<T> / new T()

✨ Features

• ✔️ The best CreateInstance ever

  • Up to 50x faster than Activator.CreateInstance<T>
  • Generic Parameters Support
  • Zero boxing/unboxing
  • TryGetValue-like TryFastNew API
  • Link Mode PublishTrimmed Support
  • Non-Public Constructor Support
  • No Generic Constraints
  • Compatible with .NET Standard 2.0
  • Multiple backend implementations.
  • Heavily tested on Win/Mac/Linux

• 🪛 Modern Compiler Integration

  • Source Generator v2 (Incremental Generator)
  • Highly Configurable (Props)
  • Multi-threaded Generation

• 🔥 Lastest C#/.NET Features Support

  • C# 8 Nullable Support
  • C# 10 Parameterless struct constructors Support (Both invokes or not)
  • WebAssembly Support

🔧 Installation

You should only use one of them

Pre-Compiled Version

dotnet add package FastGenericNew --version 3.1.0-preview1

<ItemGroup>
  <PackageReference Include="FastGenericNew" Version="3.1.0-preview1" />
</ItemGroup>

SourceGenerator Version

dotnet add package FastGenericNew.SourceGenerator --version 3.1.0-preview1

<ItemGroup>
  <PackageReference Include="FastGenericNew.SourceGenerator" Version="3.1.0-preview1" />
</ItemGroup>

SourceGeneratorV2 requires

.NET Standard 2.0 or above
C# 8.0 or above
Roslyn 4.0.1 or above
Modern IDE (Optional) [VS2022, Rider, VSCode]

📖 Examples

using FastGenericNew;

// Simply replace 'Activator' to 'FastNew'
var obj = FastNew.CreateInstance<T>();

// With parameter(s)
var obj2 = FastNew.CreateInstance<T, string>("text");
var obj3 = FastNew.CreateInstance<T, string, int>("text", 0);

// Try pattern
// NOTE: Try pattern will only check the constructor could be called (exist & callable)
//       It will not catch or handle any exceptions thrown in the constructor.
if (FastNew.TryCreateInstance<T, string>("arg0", out T result));
{
    // ...
}

Notes

With .NET Framework, Activator.CreateInstance<T>() invokes the parameterless constructor of ValueType if
the constraint is where T : new() but appears to ignore the parameterless constructor if the constraint is where T : struct.
But FastNew.CreateInstance<T>() will always invoke the parameterless constructor if it's available.

If you don't want to invoke the parameterless constructor of ValueType.
Consider to use FastNew.NewOrDefault<T>() which will never invoke the parameterless constructor of ValueType

🚀 Benchmark

Environment

BenchmarkDotNet=v0.13.1, OS=Windows 10.0.22000
AMD Ryzen 9 3900X, 1 CPU, 24 logical and 12 physical cores
.NET SDK=6.0.200-preview.22055.15
  [Host]             : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
  .NET 5.0           : .NET 5.0.14 (5.0.1422.5710), X64 RyuJIT
  .NET 6.0           : .NET 6.0.2 (6.0.222.6406), X64 RyuJIT
  .NET Framework 4.8 : .NET Framework 4.8 (4.8.4470.0), X64 RyuJIT

Reference Types

Value Types

📜 License

FastGenericNew is licensed under the MIT license.