Comment by jcelerier | Hacker News Reader

Comment by jcelerier | Hacker News Reader

Parent Full thread

> The problem with C++ is that many of those "features" are actually "anti-features". From the top of my head: operator overloading, copy-constructors, constructors, destructors, function overloading. While these "features" may make correct code easier to write, they always make incorrect code much, much harder to understand.

> For example, you find a simple line of C++ that says "y=f(x);", and it can do anything: has the parenthesis operator been overloaded? and the copy constructor? how many times is a destructor called here? What are its side effects? What instance of f is called, if none of them is defined for the actual type of x? Every single line of C++ that you have to analyze is a terrifying nightmare like this one.

I have yet to see any of this be an actual problem in real-world projects.

I have seen on the other hand a lot of people coming with these abstract "this is gonna be a problem" ideas in mind, and never wanting to touch C again after working on actual modern C++ projects.

> I have seen on the other hand a lot of people coming with these abstract "this is gonna be a problem" ideas in mind, and never wanting to touch C again after working on actual modern C++ projects.

Well, I for one had the opposite experience. I started programming in C++, and writing, reading and debugging lots of C++ code. It was not "modern" C++, since I stopped doing so around 2006. I embraced C out of personal despair with C++, especially the C++ of other people. For my personal projects, I can still enjoy using "my" favorite subset of C++ (basically, without objects nor pointers, and building the data structures by composing stl containers). Yet, anytime I have to deal with an unknown piece of C++ it is a nightmare. Especially since it is very easy to hide the behavior of the code.

>I have yet to see any of this be an actual problem in real-world projects

Just on Monday, I was bitten by a bug caused by operator overloading. I'm building a static analysis tool in C++. There's a method `getType()` that returns the qualified type of an expression. I had a call to `getType()` nested in some other calls, e.g. `expr->asAssignmentExpr()->getRHS()->getType()->getSomeQualifiedTypeProperty()`.

The creators of the `QualifiedType` type that's returned by `getType()` had overridden the class member access operator to return an UnqualifiedType. This problem took me an embarrassingly long amount of time to diagnose. The compiler error messages told me that `UnqualifiedType` doesn't have a property `getSomeQualifiedTypeProperty`, but I couldn't see why I was getting an unqualified type from a method that is supposed to return a qualified type. I searched the documentation online, searched the header files, tried reinstalling the library, nothing made sense.

Then, I learned this operator had been overloaded. So, I just needed to write `expr->asAssignmentExpr()->getRHS()->getType().getSomeQualifiedTypeProperty()`.

Ouch.

> So, I just needed to write `expr->asAssignmentExpr()->getRHS()->getType().getSomeQualifiedTypeProperty()`.

with any decent IDE you'd type something like

    expr.as<enter>.get<enter>.get<enter>.get<enter>

and you'd see the following:

https://streamable.com/xib4s0

so I fail to see how this can be an issue if you don't use prehistoric tooling

Reply on news.ycombinator.com