The next EVM version amsterdam will ship the new opcode SLOTNUM (0x4b) (see EIP-7843), which returns the beacon chain slot number of the current block. While technically uint64 is enough as return type (SLOTNUM is returned as a uint64 in big endian encoding), maybe it's better sticking to uint256 to be consistent with the other block properties. But this is up for discussion.
The next EVM version
amsterdamwill ship the new opcodeSLOTNUM(0x4b) (see EIP-7843), which returns the beacon chain slot number of the current block. While technicallyuint64is enough as return type (SLOTNUMis returned as auint64in big endian encoding), maybe it's better sticking touint256to be consistent with the other block properties. But this is up for discussion.