C# source generator to generate efficient and type-safe variant types for unmanaged types.
Get Started
$ dotnet add package ValueVariantReadme
ValueVariant
C# source generator to generate efficient and type-safe variant types for unmanaged types.
Usage
using System.ValueVariant;
[ValueVariant]
public readonly partial struct SampleVariant: IValueVariant<SampleVariant, int, long, float> { }
will generates
readonly partial struct SampleVariant: IEquatable<SampleVariant>
{
[StructLayout(LayoutKind.Explicit)]
private struct Union
{
[FieldOffset(0)] int Item1;
[FieldOffset(0)] long Item2;
[FieldOffset(0)] float Item3;
}
public enum TypeIndex : byte { None, Type1, Type2, Type3 }
private readonly Union Value;
public readonly TypeIndex Index;
public int Item1 => Index == TypeIndex.Type1 ? Value.Item1 : throw new InvalidCastException();
public long Item2 => Index == TypeIndex.Type2 ? Value.Item2 : throw new InvalidCastException();
public float Item3 => Index == TypeIndex.Type3 ? Value.Item3 : throw new InvalidCastException();
public SampleVariant(int value) { ... }
public SampleVariant(long value) { ... }
public SampleVariant(float value) { ... }
public static implicit operator SampleVariant(int value) => new SampleVariant(value);
public static implicit operator SampleVariant(long value) => new SampleVariant(value);
public static implicit operator SampleVariant(float value) => new SampleVariant(value);
public static explicit operator int(SampleVariant value) => value.Item1;
public static explicit operator long(SampleVariant value) => value.Item2;
public static explicit operator float(SampleVariant value) => value.Item3;
public bool Equals(SampleVariant other) { ... }
public override bool Equals(object obj) { ... }
public override int GetHashCode() { ... }
public override string ToString() { ... }
public static bool operator ==(SampleVariant lhs, SampleVariant rhs) { ... }
public static bool operator !=(SampleVariant lhs, SampleVariant rhs) { ... }
...
}