StorageSlot

*Library for reading and writing primitive types to specific storage slots. Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts. This library helps with reading and writing to such slots without the need for inline assembly. The functions in this library return Slot structs that contain a value member that can be used to read or write. Example usage to set ERC-1967 implementation slot:

contract ERC1967 {
// Define the slot. Alternatively, use the SlotDerivation library to derive the slot.
bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
function _getImplementation() internal view returns (address) {
return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
}
function _setImplementation(address newImplementation) internal {
require(newImplementation.code.length > 0);
StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
}
}

TIP: Consider using this library along with {SlotDerivation}.*

Functions

getAddressSlot

Returns an AddressSlot with member value located at slot.

function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r);

getBooleanSlot

Returns a BooleanSlot with member value located at slot.

function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r);

getBytes32Slot

Returns a Bytes32Slot with member value located at slot.

function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r);

getUint256Slot

Returns a Uint256Slot with member value located at slot.

function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r);

getInt256Slot

Returns a Int256Slot with member value located at slot.

function getInt256Slot(bytes32 slot) internal pure returns (Int256Slot storage r);

getStringSlot

Returns a StringSlot with member value located at slot.

function getStringSlot(bytes32 slot) internal pure returns (StringSlot storage r);

getStringSlot

Returns an StringSlot representation of the string storage pointer store.

function getStringSlot(string storage store) internal pure returns (StringSlot storage r);

getBytesSlot

Returns a BytesSlot with member value located at slot.

function getBytesSlot(bytes32 slot) internal pure returns (BytesSlot storage r);

getBytesSlot

Returns an BytesSlot representation of the bytes storage pointer store.

function getBytesSlot(bytes storage store) internal pure returns (BytesSlot storage r);

Structs

AddressSlot

struct AddressSlot {
    address value;
}

BooleanSlot

struct BooleanSlot {
    bool value;
}

Bytes32Slot

struct Bytes32Slot {
    bytes32 value;
}

Uint256Slot

struct Uint256Slot {
    uint256 value;
}

Int256Slot

struct Int256Slot {
    int256 value;
}

StringSlot

struct StringSlot {
    string value;
}

BytesSlot

struct BytesSlot {
    bytes value;
}