c#-7.0

I created a project in Visual Studio 2017 RC to check whether I can use new C# 7.0 language features in a .NET Framework 4.5 project. It seems to me that after referencing System.ValueTuple NuGet, new tuples are working fine. Is there anything else I should think about, or is this going to work? After checking System.ValueTuple NuGet dependencies, it looks like .NET Framework 4.0 is not supported. Is this the case, or is there some way to make the new language work in this runtime also? Let's go through the features new in C# 7.0 : Tuples: The System.ValueTuple package has a version for the

I was reading about new out variable features in C#7 here . I have two questions: It says We allow "discards" as out parameters as well, in the form of a _ , to let you ignore out parameters you don’t care about: p.GetCoordinates(out var x, out _); // I only care about x Q: I guess this is just an info and not a new feature of C#7 because we can do so in pre C#7.0 too: var _; if (Int.TryParse(str, out _)) ... or am I missing something here? My code gives an error when I do as mentioned in same blog: ~Person() => names.TryRemove(id, out *); * is not a valid identifier. An oversight by Mads

I am looking at the new implementations in C# 7.0 and I find it interesting that they have implemented local functions but I cannot imagine a scenario where a local function would be preferred over a lambda expression, and what is the difference between the two. I do understand that lambdas are anonymous functions meanwhile local functions are not, but I can't figure out a real world scenario, where local function has advantages over lambda expressions Any example would be much appreciated. Thanks. This was explained by Mads Torgersen in C# Design Meeting Notes where local functions were first

I decompiled some C# 7 libraries and saw ValueTuple generics being used. What are ValueTuples and why not Tuple instead? https://docs.microsoft.com/en-gb/dotnet/api/system.tuple https://docs.microsoft.com/en-gb/dotnet/api/system.valuetuple Yuval Itzchakov What are ValueTuples and why not Tuple instead? A ValueTuple is a struct which reflects a tuple, same as the original System.Tuple class. The main difference between Tuple and ValueTuple are: System.ValueTuple is a value type (struct), while System.Tuple is a reference type ( class ). This is meaningful when talking about allocations and GC

I've installed Visual Studio 15 Preview 3 and tried to use the new tuple feature static void Main(string[] args) { var x = DoSomething(); Console.WriteLine(x.x); } static (int x, int y) DoSomething() { return (1, 2); } When I compile I get the error: Predefined type 'System.ValueTuple´2´ is not defined or imported According to the blog post , this features should be "on" by default. What did I do wrong? For .NET 4.6.2 or lower, .NET Core 1.x, and .NET Standard 1.x you need to install the NuGet package System.ValueTuple : Install-Package "System.ValueTuple" Or using a package reference in VS