not a bug, a feature The issue that I’ve opened has been closed, but they gave a very good explanation. Now… In .NET 5.0 they began using on Windows (on Linux it was already present) a new library for comparing strings, the ICU library. It is the official library of the Unicode Consortium, so it … Read more
Whilst covariant return types in interfaces are not supported as of C# 9, there is a simple workaround: interface A { object Method1(); } class B : A { public string Method1() => throw new NotImplementedException(); object A.Method1() => Method1(); }
It looks like there is currently no such type available. You can implement this yourself, but beware of the implications if you need this in a production-ready way. It’s not so simple as it may seem at first sight, as this answer by @ryanholden8 demonstrates! For my use case (and as a simplified example) I … Read more
Short version Can your data type be a value type? Go with struct. No? Does your type describe a value-like, preferably immutable state? Go with record. Use class otherwise. So… Yes, use records for your DTOs if it is one way flow. Yes, immutable request bindings are an ideal user case for a record Yes, … Read more
As stated in the new C# 9 features post, The one big limitation today is that the properties have to be mutable for object initializers to work: They function by first calling the object’s constructor (the default, parameterless one in this case) and then assigning to the property setters. However, value types with readonly modifiers … Read more
C# 10.0 introduces a new feature called global using directive (global using <fully-qualified-namespace>;) which allows to specify namespaces to be implicitly imported in all files in the compilation. .NET 6 RC1 has this feature enabled by default in new project templates (see <ImplicitUsings>enable</ImplicitUsings> property in your .csproj). For Microsoft.NET.Sdk.Web next namespaces should be implicitly imported … Read more
When you use the Top-Level Program feature of C# 9, you give up the ability to put anything outside the Main method scope. Fields, properties, attributes on the Main method or Program class, setting the namespace, changing the class name, etc are all no longer available (the only exception is “importing” namespaces with using lines). … Read more
To target the various parts of the expanded class, use the appropriate attribute target. For instance: // Target the property, use `property` record Person(string FirstName, string LastName, [property: JsonIgnore] int Age); // Target the backing field of the property, use `field` record Person(string FirstName, string LastName, [field: JsonIgnore] int Age); // Target the constructor parameter, … Read more