Why does the assignment operator in C# evaluate left to right instead of right to left?

Raymond Chen July 18, 2017 Jul 18, 2017 07/18/17

When I noted some time ago that the compound assignment operator is guaranteed to evaluate its left hand side before the right hand side, there was much commenting about why the language chose that model instead of the more "obvious" evaluation order of right-then-left. In other words, instead of rewriting E1 += E2 as E1 = E1 + E2, rewrite it...

Revisions to previous discussion of the implementation of anonymous methods in C#

Raymond Chen July 17, 2017 Jul 17, 2017 07/17/17

Welcome to CLR Week. Yes, it's been a long time since the last CLR Week. Some people might consider that a feature. Anyway, I'm going to start by calling attention to some revisions to previous discussion of the implementation of anonymous methods in C#. The first revision is one most people are well aware of, namely that the scope of ...

Discussion of how to add UTF-16 support to a library that internally uses UTF-8

Raymond Chen July 14, 2017 Jul 14, 2017 07/14/17

A customer was incorporating an external library that internally manages file names in UTF-8. They wanted to add UTF-16 support¹ and to avoid having to make a lot of changes to the library to change its internal data format, they figured it'd be less risky to keep the internal format as UTF-8 and convert the file names from UTF-16 to UTF-...

Customizing the window handle for item enumeration in IShellItem

Raymond Chen July 13, 2017 Jul 13, 2017 07/13/17

Some time ago, I showed how to customize the enumeration flags used when enumerating items with IShell­Item. This controls the grfFlags parameter passed to the IShell­Folder::Enum­Objects method, but what about the hwndOwner parmaeter? How to do you customize the window handle? The window handle for the enumeration comes from the ...

Why is the maximum number of TLS slots 1088? What a strange number.

Raymond Chen July 12, 2017 Jul 12, 2017 07/12/17

Commenter Max noted that the maximum number of TLS slots is 1088 and wondered why such a strange number. "I mean, it does not look like a perfect number in terms of 2-based numeric system." It looks a little better in base 2. The value is 10001000000 which breaks down as 1024 + 64. When TLS was first introduced, the number of available TLS ...

On the circular path from RAII to crazy-town back to RAII: Thoughts on emulating C#’s using in C++

Raymond Chen July 10, 2017 Jul 10, 2017 07/10/17

Some follow-up notes on Emulating the C# using keyword in C++, primarily for the benefit of people from reddit who stumbled into the series and didn't understand the context of the discussion, because this was really part 6 of the series begun the previous week, even though it wasn't labeled as such. (And the title itself was a party trick ...

How can I tell whether two paths reside on the same underlying volume, so I can know whether they can be hard-linked?

Raymond Chen July 7, 2017 Jul 7, 2017 07/7/17

A customer wanted to know whether there was a way to determine whether two paths reside on the same underlying volume. They were concerned that due to tricks like SUBST and volume mount points, the naïve algorithm of comparing drive letters may prove inadequate. You can use Get­File­Information­By­Handle to get the volume...

Debugging tip: Use .frame /r to recover nonvolatile registers from the stack frame

Raymond Chen July 6, 2017 Jul 6, 2017 07/6/17

A customer was debugging a crash dump (using a debugger that is based on the Windows debugger engine) and observed that when they used the k command, the "Args to Child" values didn't make any sense, and they suspect that the values are not accurate. They were wondering if there were any tips for recovering the actual parameters. The ...

How fair are SRW locks, particularly when there are both readers and writers?

Raymond Chen July 5, 2017 Jul 5, 2017 07/5/17

A customer wanted to know about the order of lock acquisition in the SRWLOCK functions. They note that the documentation says, There is no guarantee about the order in which threads that request ownership will be granted ownership; SRW locks are neither fair nor FIFO. They were worried about starvation. For example, suppose thread 1 ...