From Python to C++

A few days months ago someone asked me (well, a group that happened to include me) for advice on learning C++, for a Python speaker.

Ouch. What do you tell someone who's getting started with C++? What can you say that won't scare them away?

You could tell them the good reason behind many of C++'s complexities: that it's lower-level than Python, especially in data representation. You could tell them that's good when you care about efficiency and bad the rest of the time. But they probably already know that, and it's not the most useful sort of information.

You could give them bits of good advice, and warn them of the dangers. There are hundreds of specific tips and tricks they'll need to learn, but they wouldn't understand most of them until they knew more of the language. Failing that, you could at least give them some general warnings:

• There is much less agreement on good style. There are often multiple incompatible accepted ways to do something, like, say, basic I/O. Some of the advanced features are painful to the point of uselessness.
• Parts of the standard library are dangerously broken.
• For reasons of backward-compatibility and low-level-ness, C++ is complicated. Don't expect to keep the whole language in your head, the way you can for Python.
• Collection support is pretty bad.
• There is a way to do anything, but it may be more trouble than it's worth.
• A lot of C++ tutorial material appears to be written for and by idiots.
• Manual memory management is hard. If it accounts for half of your bugs, that's normal.

But they'd forget all that before they learned enough to apply it. Is there a shorter summary of the differences between C++ and Python?

I'd put it this way: you can't trust C++. Python may have a few warts, but for the most part it makes sense, because someone designed it. Most features are there for a good reason, and the obvious way to do things is generally the right way. The language is a garden, planted with useful things, and its pathways are generally safe and will lead you somewhere useful.

C++, on the other hand, is a wilderness. It may have almost as many fruits and flowers as the garden, but they're hidden among poisonous plants and thorns, and guarded by poisonous snakes and tigers. There are paths, but they're hard to follow, and some of them lead off cliffs or into swamps or snares. To navigate C++, you must be your own guide, because the language won't help you.

I don't hate C++. I admire the degree to which it can support higher-level constructs without losing its low-level powers. But it's a hard language to introduce someone to, especially someone who's coming from Python and therefore expects languages to make sense.