System Extensions

System.Action

HasInvocation

if (action.HasInvocation()) {
    ...
}
// => alias of
if (action.GetInvocationList().Length > 0) {
    ...
}

System.Func

HasInvocation

if (func.HasInvocation()) {
    ...
}
// => alias of
if (func.GetInvocationList().Length > 0) {
    ...
}

Matrix4x4

Casts

System.Numerics.Matrix4x4 <-> UnityEngine.Matrix4x4

var sysMat = new System.Numerics.Matrix4x4();
var uniMat = sysMat.ToUnity();
//--
var uniMat = new UnityEngine.Matrix4x4();
var sysMat = uniMat.ToSystem();

IO

DirectoryInfo:GetFilesRecursively

Likes directory.GetFiles() but recursively.

DirectoryInfo:CopyTo

Copy a directory content to another recursively.

Stream:ReadAllBytes

Read all bytes in a stream.

// example from TextureUtility, open an embedded texture
icon = new Texture2D(128, 128);
...
using(var stream = assembly.GetManifestResourceStream(path)) {
    if (stream != null) {
        icon.LoadImage(stream.ReadAllBytes());
        ...
    }
}