this post was submitted on 15 May 2025
1089 points (98.5% liked)

Programmer Humor

23527 readers
2186 users here now

Welcome to Programmer Humor!

This is a place where you can post jokes, memes, humor, etc. related to programming!

For sharing awful code theres also Programming Horror.

Rules

founded 2 years ago
MODERATORS
 
top 50 comments
sorted by: hot top controversial new old
[–] [email protected] 179 points 2 weeks ago (3 children)
typedef struct {
    bool a: 1;
    bool b: 1;
    bool c: 1;
    bool d: 1;
    bool e: 1;
    bool f: 1;
    bool g: 1;
    bool h: 1;
} __attribute__((__packed__)) not_if_you_have_enough_booleans_t;
[–] [email protected] 43 points 2 weeks ago

You beat me to it!

[–] [email protected] 41 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

Or just std::bitset<8> for C++. Bit fields are neat though, it can store weird stuff like a 3 bit integer, packed next to booleans

[–] [email protected] 10 points 2 weeks ago* (last edited 2 weeks ago)

That's only for C++, as far as I can tell that struct is valid C

[–] [email protected] 16 points 2 weeks ago (1 children)

This was gonna be my response to OP so I'll offer an alternative approach instead:

typedef enum flags_e : unsigned char {
  F_1 = (1 << 0),
  F_2 = (1 << 1),
  F_3 = (1 << 2),
  F_4 = (1 << 3),
  F_5 = (1 << 4),
  F_6 = (1 << 5),
  F_7 = (1 << 6),
  F_8 = (1 << 7),
} Flags;

int main(void) {
  Flags f = F_1 | F_3 | F_5;
  if (f & F_1 && f & F_3) {
    // do F_1 and F_3 stuff
  }
}
load more comments (1 replies)
[–] [email protected] 139 points 2 weeks ago (1 children)
[–] [email protected] 153 points 2 weeks ago (14 children)

And compiler. And hardware architecture. And optimization flags.

As usual, it's some developer that knows little enough to think the walls they see around enclose the entire world.

[–] [email protected] 13 points 2 weeks ago (1 children)

Fucking lol at the downvoters haha that second sentence must have rubbed them the wrong way for being too accurate.

load more comments (1 replies)
load more comments (13 replies)
[–] [email protected] 132 points 2 weeks ago (4 children)

I set all 8 bits to 1 because I want it to be really true.

[–] [email protected] 93 points 2 weeks ago* (last edited 2 weeks ago) (8 children)

01111111 = true

11111111 = negative true = false

[–] [email protected] 47 points 2 weeks ago (3 children)
[–] [email protected] 27 points 2 weeks ago (3 children)
[–] [email protected] 20 points 2 weeks ago

100001111 = maybe not

load more comments (2 replies)
load more comments (2 replies)
[–] [email protected] 33 points 2 weeks ago (4 children)

What if it's an unsigned boolean?

[–] [email protected] 24 points 2 weeks ago

Cthulhu shows up.

load more comments (2 replies)
[–] [email protected] 12 points 2 weeks ago

Could also store our bools as floats.

00111111100000000000000000000000 is true and 10111111100000000000000000000000 is negative true.

Has the fun twist that true & false is true and true | false is false .

load more comments (5 replies)
[–] [email protected] 14 points 2 weeks ago (1 children)

TIL, 255 is the new 1.

Aka -1 >> 1 : TRUE

load more comments (1 replies)
[–] [email protected] 12 points 2 weeks ago

I was programming in assembly for ARM (some cortex chip) and I kid you not the C program we were integrating with required 255, with just 1 it read it as false

[–] [email protected] 10 points 2 weeks ago

You jest, but on some older computers, all ones was the official truth value. Other values may also have been true in certain contexts, but that was the guaranteed one.

[–] [email protected] 93 points 2 weeks ago (1 children)

string boolEnable = "True";

[–] [email protected] 39 points 2 weeks ago (1 children)
load more comments (1 replies)
[–] [email protected] 90 points 2 weeks ago (6 children)

Then you need to ask yourself: Performance or memory efficiency? Is it worth the extra cycles and instructions to put 8 bools in one byte and & 0x bitmask the relevant one?

[–] [email protected] 37 points 2 weeks ago

Sounds like a compiler problem to me. :p

[–] [email protected] 23 points 2 weeks ago (4 children)

A lot of times using less memory is actually better for performance because the main bottleneck is memory bandwidth or latency.

load more comments (4 replies)
load more comments (4 replies)
[–] [email protected] 54 points 2 weeks ago (1 children)

Wait till you find out about alignment and padding

load more comments (1 replies)
[–] skisnow 50 points 2 weeks ago (6 children)

Back in the day when it mattered, we did it like

#define BV00		(1 <<  0)
#define BV01		(1 <<  1)
#define BV02		(1 <<  2)
#define BV03		(1 <<  3)
...etc

#define IS_SET(flag, bit)	((flag) & (bit))
#define SET_BIT(var, bit)	((var) |= (bit))
#define REMOVE_BIT(var, bit)	((var) &= ~(bit))
#define TOGGLE_BIT(var, bit)	((var) ^= (bit))

....then...
#define MY_FIRST_BOOLEAN BV00
SET_BIT(myFlags, MY_FIRST_BOOLEAN)

load more comments (6 replies)
[–] [email protected] 39 points 2 weeks ago* (last edited 2 weeks ago) (3 children)

The 8-bit Intel 8051 family provides a dedicated bit-addressable memory space (addresses 20h-2Fh in internal RAM), giving 128 directly addressable bits. Used them for years. I'd imagine many microcontrollers have bit-width variables.

bit myFlag = 0;

Or even return from a function:

bit isValidInput(unsigned char input) { // Returns true (1) if input is valid, false (0) otherwise return (input >= '0' && input <= '9'); }

[–] [email protected] 16 points 2 weeks ago (4 children)

Nothing like that in ARM. Even microcontrollers have enough RAM that nobody cares, I guess.

[–] [email protected] 10 points 2 weeks ago

ARM has bit-banding specifically for this. I think it’s limited to M-profile CPUs (e.g. v7-M) but I’ve definitely used this before. It basically creates a 4-byte virtual address for every bit in a region. So the CPU itself can’t “address” a bit but it can access an address backed by only 1 bit of SRAM or registers (this is also useful to atomically access certain bits in registers without needing to use SW atomics).

load more comments (3 replies)
[–] [email protected] 13 points 2 weeks ago

We could go the other way as well: TI's C2000 microcontroller architecture has no way to access a single byte, let alone a bit. A Boolean is stored in 16-bits on that one.

load more comments (1 replies)
[–] [email protected] 36 points 1 week ago (1 children)

In the industrial automation world and most of the IT industry, data is aligned to the nearest word. Depending on architecture, that's usually either 16, 32, or 64 bits. And that's the space a single Boolean takes.

[–] [email protected] 18 points 1 week ago (1 children)

That's why I primarily use booleans in return parameters, beyond that I'll try to use bitfields. My game engine's tilemap format uses a 32 bit struct, with 16 bit selecting the tile, 12 bit selecting the palette, and 4 bit used for various bitflags (horizontal and vertical mirroring, X-Y axis invert, and priority bit).

[–] [email protected] 28 points 1 week ago (5 children)

Bit fields are a necessity in low level networking too.

They're incredibly useful, I wish more people made use of them.

I remember I interned at a startup programming microcontrollers once and created a few bitfields to deal with something. Then the lead engineer went ahead and changed them to masked ints. Because. The most aggravating thing is that an int size isn't consistent across platforms, so if they were ever to change platforms to a different word length, they'd be fucked as their code was full of platform specific shenanigans like that.

/rant

load more comments (5 replies)
[–] [email protected] 34 points 2 weeks ago (1 children)
[–] [email protected] 11 points 2 weeks ago* (last edited 2 weeks ago)

Weird how I usually learn more from the humor communities than the serious ones... 😎

[–] [email protected] 32 points 2 weeks ago (1 children)

std::vector<bool> fits eight booleans into one byte.

load more comments (1 replies)
[–] [email protected] 26 points 2 weeks ago (11 children)

It's far more often stored in a word, so 32-64 bytes, depending on the target architecture. At least in most languages.

load more comments (11 replies)
[–] [email protected] 23 points 2 weeks ago (1 children)

if wasting a byte or seven matters to you, then then you need to be working in a lower level language.

[–] MystikIncarnate 27 points 2 weeks ago (1 children)

It's 7 bits....

Pay attention. 🤪

[–] [email protected] 29 points 2 weeks ago (1 children)

7 bytes! Look at Mr. Moneybags here!

load more comments (1 replies)
[–] [email protected] 22 points 2 weeks ago (1 children)

Joke’s on you, I always use 64 bit wide unsigned integers to store a 1 and compare to check for value.

load more comments (1 replies)
[–] [email protected] 21 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

I have a solution with a bit fields. Now your bool is 1 byte :

struct Flags {
    bool flag0 : 1;
    bool flag1 : 1;
    bool flag2 : 1;
    bool flag3 : 1;
    bool flag4 : 1;
    bool flag5 : 1;
    bool flag6 : 1;
    bool flag7 : 1;
};

Or for example:

struct Flags {
    bool flag0 : 1;
    bool flag1 : 1:
    int x_cord : 3;
    int y_cord : 3;
};
load more comments (1 replies)
[–] [email protected] 21 points 1 week ago (3 children)
load more comments (3 replies)
[–] [email protected] 17 points 2 weeks ago (1 children)
load more comments (1 replies)
[–] [email protected] 16 points 2 weeks ago (1 children)

just like electronic components, they sell the gates by the chip with multiple gates in them because it's cheaper

load more comments (1 replies)
[–] [email protected] 14 points 1 week ago (6 children)

Are you telling me that no compiler optimizes this? Why?

[–] [email protected] 32 points 1 week ago

It would be slower to read the value if you had to also do bitwise operations to get the value.

But you can also define your own bitfield types to store booleans packed together if you really need to. I would much rather that than have the compiler do it automatically for me.

[–] [email protected] 23 points 1 week ago (4 children)

Well there are containers that store booleans in single bits (e.g. std::vector<bool> - which was famously a big mistake).

But in the general case you don't want that because it would be slower.

load more comments (4 replies)
load more comments (4 replies)
load more comments
view more: next ›