🐇 It may be useful, though. It looks like syntactic sugar for a const pointer plus malloc, but implicitness is usually not ideal. It also appears to use the stack.

🐢 I haven’t looked into the details, but it may be useful in some cases. I don’t think it can replace pointer usage if it uses the stack, though. Stack sizes are usually small, and having arrays that can fill them up is not a good approach. Another feature is complex number support. It seems from the lecture that this is also a bit of a half-baked feature.

🐇 What is the difference between this and using a struct with two float fields?

🐢 There are operators (+, -, *, or ==) that support these. Since there is no operator overloading in C, having a separate complex number type may be useful.

🐇 The example looks like double complex cx = 1.0 + 3.0*I; and yes, this may be useful if you’re frequently using complex numbers in your code. But I think it’s unnecessary in most cases. There shouldn’t be such a frequent need for complex numbers, right?

🐢 A good complex number library will probably provide more than the built-in type, such as vectors for these numbers. A dedicated library will still be needed in most cases, I believe.

🐇 Another feature added to C is that struct members can now be initialized by name or index. You can initialize an array like int a[6] = { [3] = 29, [2] = 14 };, and it will initialize only those specific members.

🐢 Ah, this is much more useful than complex numbers for the general case.

🐇 There is also a span syntax: int a[10] = {1, 2, [2 ... 4] = 3, [5] = 30};.

🐢 That is really neat.

🐇 It’s also possible to omit the initial length, so the initializer values determine the size of the array. For example, int a[] = {1, 3, [30] = 55, [9090] = 1010}; will result in an array of length 9091.

🐢 How is this used with structs?

🐇 Instead of [], in struct initializers, we use the dot notation, like struct Point p1 = { .x=0, .y=10 };.

🐢 This is really useful and would keep much of the initialization code simpler.

🐇 There is also a way to initialize arrays of structs, like:

struct points pts[5] = { [0].x = 10, [0].y = 20, [3].x = 100 };

🐢 This feature is a nice addition to C; I really like it.

i3-msg workspace "n"

It’s possible to get a section from a Markdown file with a command like:

sed -n -e '/^#/,/^#/p'

It is also possible to use line numbers instead of regexes. The p at the end is the print command, which can be replaced by, for example, d to delete the lines.

I have used ~ several times in scripts, but it may not always expand as expected depending on the environment. Use $HOME to refer to the home directory; it is much more reliable and always works.