C# 6, you dirty dog!

PIEBALDconsult

OK, so after my earlier post, I found that I was compiling with C# 6 turned on without realizing it. I prefer to use new features of C# only if they offer me something useful. I use only a few features of C# 3, and no newer features than that, so I want my code to compile with C# 3 selected, but I hadn't been bothering to specify it, I had left it set to the default (my fault of course). So yesterday I spent some time ensuring that my libraries and utilities will compile with C# 3. And BOOM! one of my recent utilities complained: error CS0840: '[REDACTED].CommonBase.ScriptXML.get' must declare a body because it is not marked abstract or extern. Automatically implemented properties must define both get and set accessors. and error CS8026: Feature 'readonly automatically implemented properties' is not available in C# 3. Please use language version 6 or greater. (Messages from two versions of CSC.EXE . I'm not sure which is the more helpful.) It turns out that a few months back, I had made a copy/paste error. I had intended to write: public System.Xml.XmlNode ScriptXML { get ; private set ; } but, because I had copied: System.Xml.XmlNode ScriptXML { get ; } from an Interface definition, I wound up with: public System.Xml.XmlNode ScriptXML { get ; } I had forgotten to add the private set ; (or do I want it protected?) and the compiler (set to C# 6) was fine with it! :elephant: ! Yeah, OK, so it's not actually a bug, but it's a coding error and I wish I had been alerted to it when I first wrote it. Going forward, I am specifying /langversion:3 until I find a useful feature of some future version. Bonus: My work laptop has these two versions of CSC.EXE: C:\Windows\Microsoft.NET\Framework\v4.0.30319\csc.exe Supports up to C# 5 C:\Program Files (x86)\MSBuild\14.0\Bin\csc.exe Supports up to C# 6 and, of course, I had been using the newer version (as you do). I expect the newer version was installed in the past month. But I found that utilities compiled with the newer version won't run on the servers, so I had to revert to using the older version when I compile on the command line, which is the norm for my utilities. Yes, I do use Visual Studio (2015) on occasion, but not for making release builds of command-line utilities to deploy to the servers.

Richard Deeming

PIEBALDconsult wrote:

it's a coding error

That depends on your intention. If you wanted a property which could be modified by any code within your class, then yes. If you wanted a true "read-only" property, which can only be initialized in the constructor or an initializer, then omitting the private set; is perfectly correct.

public class Foo
{
public int Bar { get; private set; }
public int Baz { get; }

public Foo(int bar, int baz)
{
    Bar = bar; // Fine
    Baz = baz; // Also fine
}

public void Groot()
{
    Bar = 42; // Compiles and runs
    Baz = 42; // Compiler error CS0200 - Property or indexer 'Foo.Baz' cannot be assigned to -- it is read-only
}

}

"These people looked deep within my soul and assigned me a number based on the order in which I joined." - Homer

PIEBALDconsult

Richard Deeming wrote:

could be modified by any code within your class

Yes. Even though I don't intend to change it. I prefer to leave that option open, possibly even making it protected instead.

Richard Deeming wrote:

can only be initialized in the constructor

No. I prefer not to tie my hands that tightly. And I didn't realize that was the implication. I do occasionally make a readonly field though. That "feature" may be good, but the implementation is not -- adding a limitation by not writing something. X|

James Curran

>> That "feature" may be good, but the implementation is not -- adding a limitation by not writing something. Say what? You are not "adding a limitation". You are not adding a feature (by not writing something). Or, written in the positive, You need to write something to add the capability. That's perfectly natural and correct.

Truth, James

jochance

I was just sure this was going to be about how sometime readonly isn't really readonly. :)

englebart

Command line utilities should be written in notepad and compiled with csc.exe.

PIEBALDconsult

Yes, which is what I do... as far as you know ;) . (I actually wrote my own simple IDE.) I don't like that notepad can't be flexible on TABs. I do use it for XML though.