New .NET Library Does Deep Cloning Right

Deep cloning objects has been a major pain point for me for a long time. Recently, I’ve run into a case where after cloning a dictionary ContainsKey no longer worked for items cloned.

This inspired me to create a new library FastCloner for the modern .NET Core that would just work. Out of the box. Cyclic references, delegates, read-only collections… as many edge cases covered as possible.

There are still some scenarios, such as unmanaged memory, where cloning can go awry, but it should be a major improvement over the prior art. Feel free to check it out!

Using FastCloner is straightforward:

1. Install the library:

dotnet add package FastCloner

2. Clone your objects:

using FastCloner.Code;
var clone = FastCloner.DeepClone(new { Hello = "world", MyList = new List<int> { 1 } });

Excluding fields & properties from cloning is simple as well:

private class TestPropsWithIgnored
{
    [FastClonerIgnore] // <-- decorate such members with [FastClonerIgnore]
    public string B { get; set; } = "My string";

    public int A { get; set; } = 10;
}

TestPropsWithIgnored original = new TestPropsWithIgnored { A = 42, B = "Test value" };
TestPropsWithIgnored clone = original.DeepClone(); // clone.B is null (default value of a given type)

As a bonus, FastCloner also supports shallow cloning:

// the list is shared between the two instances
var clone = FastCloner.ShallowClone(new { Hello = "world", MyList = new List<int> { 1 } });

Intrigued? Try it out:

https://github.com/lofcz/FastCloner