System.int and other primitives types work? I never understood how it was possible to make primitives structs and I wonder if I could make my own numeric type.
Assuming we're talking about a C# compiler which targets the Common Language Infrastructure (CLI), as almost everything does, it basically uses the primitive types exposed by the CLI.
There are effectively three levels of support to consider:
System.Decimal. This is also part of the Common Type System (CTS) which means that if you create a
const decimalin C#, you can still consume it in VB, for example. But there's still no direct IL support.
BigInteger- you can write your own ones of these.
The middle ground of the second bullet allows C# to have decimal literals and decimal constants, neither of which are possible for the third bullet. For example,
BigInteger doesn't have language support, so you can't write:
// This isn't valid BigInteger bigInteger = 123456789012345678901234567890;
You'd have to parse a string representation instead. Likewise you can't have a
(In theory it would be possible to have a type with support in C# but not in the CTS. I don't know of any such types.)
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