Share your repls and programming experiences

← Back to all posts
I Made my Own Data Type (C++)!
h
DynamicSquid (3245)

It's called "dsq::squid". The namespace "dsq" stands for "dynamic squid". If you want to see how I created this, take a look at the attached repl. Also, if you want to learn how to make your own data type, check out this tutorial. Otherwise, let's see what "squid" can do!


So my data type can actually accommodate most primitive types, making it dynamic. It can hold an integer, string, float, and a few more! Here's the basic syntax:

dsq::squid<data_type> variable_name = value;

dsq::squid<int> integerVariable = 10;
dsq::squid<char> characterVariable = 's';

Here's the list of types it can hold:

  • bool
  • char
  • short, int, long
  • float, double
  • std::string

And the cool thing is, each type has it's own special method! Now let's take a look at bool.


Boolean Squids

// we'll be using the namespace for now
using namespace dsq;

squid<bool> boolVar = true;

// you can even assign it to another boolean!
bool anotherBoolVar = boolVar;

// also works in if statements!
if (boolVar)
  std::cout << "boolVar is " << boolVar; // and you can use it with `std::cout`!

// `.size()` returns the size in bytes of the variable
size_t sizeOfBool = boolVar.size();

As you can see, with the power of overloaded operators, we can make the object boolVar function like a traditional boolean!

Well, that's just bool. Next, characters!


Character Squid

squid<char> charVar = 's';

// just like bool, 'charVar' behaves like a traditional character
char anotherCharVar = charVar;

// you can even increment it! (the ascii value)
++charVar; // prefix and
charVar++; // postfix!

// gets the ascii value!
int asciiValue = charVar.ascii();

// just like bool, you can get the size of the variable
size_t sizeOfChar = charVar.size();

What's special about char is that you can actually get the ascii value of it! Should come in handy sometimes.

Well, next up, integers!


Integer Squids

// works with short and long as well
squid<int> intVar = 10;

// just like the rest, 'intVar' functions like a traditional int variable
int anotherIntVar = intVar;

// also supports increments
++intVar;
intVar++;

// and more math operations
intVar += 10;
intVar %= 3;

// and even additon!
anotherIntVar = intVar + 10;

// and even rounding!
intVar = intVar.round();

// you can even convert it to a string!
std::string = intVar.to_str();

What makes the int type so special is the round method!

intVar.round(place, method);

The place is based 10. So you can round it by the 10th place, 100th place, or even 100000th place. The default is 10.

The method is how you would like to round it. Up, down, or normally.

Up - 3.14 becomes 3.2;
Down - 3.14 becomes 3.1
Normal - 3.14 becomes 3.1

There's also a to_str() method which converts the int to a string.

Next up, decimals!


Decimal Squids

So for decimals, it's actually very similar to ints, but the round function works a little differently. You specify how many decimals places you would like to remove (default is 3).

squid<double> doubleVar = 3.1415;
doubleVar = doubleVar.round(); // default is 3
doubleVar = doubleVar.round(1); // one decimal place

Another special feature is the decimal_places() method, which counts the number of decimal places. It returns and int.

doubleVar.decimal_places();

And lastly, strings!


String Squids

squid<std::string> strVar = "dynamic ";

// concatenate strings
strVar += "squid";

// multiple strings!
strVar *= 2; // dynamic squiddynamic squid

// access a character from the string!
char letter = strVar[2];

// get the length
int strLen = strVar.length()

// and erase it! works just like `.erase()`
strVar.erase(1, 5);

So a few things here. Subscript operator, multiplication, length, and erase.


And yeah! That's all the data types of the dsq::squid data type. Comment below if you want me to add more. Also, one more thing:

// you can count the number of squids!!!
int numberOfSquidVariables = countSquids;

Don't forget to upvote!

Commentshotnewtop
Codemonkey51 (836)

WAIT:

attacked repl

YOU ATTACKED A REPL HOW DARE YOU MONSTER

xxpertHacker (382)

I don't know, I see C casts in there (int), and I can't do ++ on the bool.
Some of this could've had better performance, for example, constexpr for .size.

constexpr int size = sizeof variable;

Also, why was it a function?

Really, most of this uses the C++ stdlib, makes it private, and exposes even less than std:: does.

Thinking about this... I might be able to make something relatively useful.

Now really, I was preparing to make a type-safe output system relatively similar to (w)cout and I had seen squid& as the return value of the operator, which is a reference to an object of the type squid, yet attempts to do so in my own code fail.

DynamicSquid (3245)

@StudentFires a type safe output system would be kind cool

xxpertHacker (382)

@DynamicSquid cout is type-safe already, but like printf, you can easily do printf("%d", "die system, die"). But can you explain how the squid& works?

DynamicSquid (3245)

@StudentFires oh you mean like for this: squid& operator ++ () { ++variable; return *this; }?

xxpertHacker (382)

@DynamicSquid yes, I have no clue as to how that's working, as I'm far from an expert on C++ classes.

DynamicSquid (3245)

@StudentFires oh, okay. here, think of it like this:

int nums[] = { 1, 2, 3, 4, 5 };

int& getValue(int index)
{
  return nums[index];
}

int main ()
{
  // without the reference return type, you couldn't do this
  getValue(2) = 7;
}

So the reference return type basically turns the function into the actual value it's returning.

xxpertHacker (382)

@DynamicSquid I know what references are, yet I haven't returned one. Interesting.

Jakman (441)

I dont believe this.

Jakman (441)

@DynamicSquid never seen the making of a data type. This is just cool to me.

DynamicSquid (3245)

@Jakman oh cool. it's basically just a bunch of template classes and overloaded operators

DynamicSquid (3245)

@Jakman i think C++ is a better language for making your own data type than say python, since C++ supports some necessary features

Jakman (441)

@DynamicSquid would not personally try data type making in a dynamically typed language.