3 ms·

What you actually want is function overloading, which C can't support since C functions map directly to elf symbols, and all assembly functions are vararg with

What you actually want is function overloading, which C can't support since C functions map directly to elf symbols, and all assembly functions are vararg with all arguments being WORDs. (That's how it is in elf, *nix and x64, don't know much about other platforms)

FrozenVoid 6y ago
_Generic macros provide similar functionality to function overload(which in C++ involves name mangling, that will never be accepted for C) https://en.cppreference.com/w/c/language/generic https://en.cppreference.com/w/c/language/generic
lldbg 6y ago
In C++, name mangling is used to solve this issue
mjburgess 6y ago
You don't need a vtable for overloading; that is just runtime polymorphism ("ad hoc polymorphism". Function overloading can be done compile time, eg., parametrically: add(3.0, 1.0) -> compile to add_float32_float32 add(1, 2) -> compile to add_int32_int32
- fctorial 6y ago
  As I said, `add` function in C maps to a symbol named `add` in assembly. You're demangling the function name, which is what C++ does.
  - mjburgess 6y ago
    Sure, you're right. I guess we'd need C to have a special syntax to compile in something like a vtable add_f32_f32(x, y) calls add(MAGIC_NO, x, y) and add has a big switch on MAGIC_NO for selecting implementation... You'd need a keyword for this, "multi int add(int a, int b) ..."
    - jcelerier 6y ago
      such complications where this is what C++ gives you natively
HexDecOctBin 6y ago
Not necessarily, they could standardize it as a syntax like _Generic, to make it so that the user has to choose a unique name for each function, but then they can all be called by a common name.
jws 6y ago
Clang has C function overloading. I use it in a reasonable sized code base. It really cleans up the source code, you end up skipping a lot of the type name or package name parts of function names which accumulate in larger projects leaving a much cleaner source to read. 100% recommend.

FrozenVoid 6y ago

_Generic macros provide similar functionality to function overload(which in C++ involves name mangling, that will never be accepted for C) https://en.cppreference.com/w/c/language/generic https://en.cppreference.com/w/c/language/generic

lldbg 6y ago

In C++, name mangling is used to solve this issue

mjburgess 6y ago

You don't need a vtable for overloading; that is just runtime polymorphism ("ad hoc polymorphism". Function overloading can be done compile time, eg., parametrically: add(3.0, 1.0) -> compile to add_float32_float32 add(1, 2) -> compile to add_int32_int32

fctorial 6y ago
As I said, `add` function in C maps to a symbol named `add` in assembly. You're demangling the function name, which is what C++ does.
- mjburgess 6y ago
  Sure, you're right. I guess we'd need C to have a special syntax to compile in something like a vtable add_f32_f32(x, y) calls add(MAGIC_NO, x, y) and add has a big switch on MAGIC_NO for selecting implementation... You'd need a keyword for this, "multi int add(int a, int b) ..."
  - jcelerier 6y ago
    such complications where this is what C++ gives you natively

HexDecOctBin 6y ago

Not necessarily, they could standardize it as a syntax like _Generic, to make it so that the user has to choose a unique name for each function, but then they can all be called by a common name.

jws 6y ago

Clang has C function overloading. I use it in a reasonable sized code base. It really cleans up the source code, you end up skipping a lot of the type name or package name parts of function names which accumulate in larger projects leaving a much cleaner source to read. 100% recommend.