What Are SCARY Iterators?

re: What Are SCARY Iterators?

CornedBee — Tue, 10 Apr 2012 12:57:45 GMT

> First, the STL gets to break binary compatibility between major releases (which is wonderful).

Yes ... and starting with VS10 it even refuses to link against incompatible versions (provided they are VS10+ too), which is also wonderful. Of course, that only means that I'm protected against linking my VS11 program against a VS10 library, not my VS10 program against a VS8 library. If you do that, you still get surprising runtime crashes.

To think that you guys implemented a compiler/linker extension to achieve this, when the C++11 standard has inline namespaces to achieve the same thing, only in a way that would protect against the second class of errors too.

re: What Are SCARY Iterators?

Stephan T. Lavavej - MSFT — Mon, 09 Apr 2012 13:38:31 GMT

Narom: First, the STL gets to break binary compatibility between major releases (which is wonderful). Second, I have an idea to reduce the cost of our extensive correctness checks in debug mode, which I'd like to try someday. (Currently, we track iterators with a singly-linked list; I suspect that a doubly-linked list would be significantly more efficient when a container has many iterators.) However, it will always be quite expensive in absolute terms, since we need to take locks for operations that look like reads.

re: What Are SCARY Iterators?

Sarfaraz — Sun, 08 Apr 2012 04:12:08 GMT

I think the acronym RAII (for "Resource Acquisition Is Initialization") was given by Bjarne Stroustrup himself.

re: What Are SCARY Iterators?

Narom — Sat, 07 Apr 2012 14:28:05 GMT

Hi, thanks for improvements! Maybe you can (binary compatibly!) reduce the increadible slowdown of iterators in debug mode in next release? Try something like std:vector<std:list<int>:iterator>. That would be Great!

re: What Are SCARY Iterators?

Diego Dagum - MSFT — Fri, 06 Apr 2012 17:53:30 GMT

Indeed it is harder, fery. But have you been following the syntax improvements achieved with the latest standard C++11? I recommend you this reading by Herb Sutter as I see you talking about garbage collection and I feel, correct me if I'm wrong, like you may not be aware about improvements like smart pointers in this case. Herb's paper is here: herbsutter.com/elements-of-modern-c-style

re: What Are SCARY Iterators?

fery — Fri, 06 Apr 2012 17:24:23 GMT

C++ syntax is very hard.Microsoft must implement new native language such as C# syntax.

C++ is depend to 1980.

new native language with garbage collection and ...

re: What Are SCARY Iterators?

Diego Dagum - MSFT — Fri, 06 Apr 2012 17:00:40 GMT

Yeah... I'm not a 100% sure but I believe that he's the same guy who created the acronym RAII (Resource Acquisition Is Initialization). Although if I'm right about the guy, he still owns the credits for having invented the programming language which, without it, we wouldn't be discussing in this space. :-)

re: What Are SCARY Iterators?

Ash — Fri, 06 Apr 2012 16:50:39 GMT

The person who coined the name certainly went to unimaginable lengths to come up with a cool name!