E. OOP Features

Back to Solidity Feature Support

Feature	Status	Notes
Single inheritance	✅	C3 linearization with flatten_contract_inheritance.
Multiple inheritance	✅	Diamond inheritance detected. Constructor arg conflicts reported.
interface	✅	Interface types tracked. Methods validated.
abstract contract	✅	Unimplemented functions detected. Non-abstract contracts get actionable errors.
library	⚠️	Builtin devpack libraries are compiler intrinsics. User-defined libraries are merged/inlined into consuming contracts.
using X for Y	✅	Library member-call syntax fully supported. using X for * and using {f,g} for T included.
super keyword	✅	Supported via inheritance flattening with __super_ method preservation.
is (inheritance)	✅	Inheritance specifiers fully processed.
Constructor chaining	✅	Base constructor arguments resolved from inheritance specifiers.
Event inheritance	✅	Interface events collected recursively via collect_interface_events_recursive.

Partial OOP details

library — The devpack ships built-in libraries (Runtime, Storage, Syscalls, etc.) that are compiler intrinsics — they lower directly to syscalls and native contract calls. User-defined libraries are merged into the consuming contract. internal calls work directly, and public / external library functions are accepted but normalized to internal helpers with warnings. Libraries still cannot maintain mutable state or behave like separately deployed/linkable EVM libraries.

// ✅ Works — using devpack intrinsic library
import "devpack/libraries/Runtime.sol";
require(Runtime.checkWitness(sender), "unauthorized");

// ✅ Works — user-defined library with internal functions
library MathLib {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        return a + b;
    }
}

using MathLib for uint256;
uint256 result = x.add(y);

---