Description:
Proxy contract enabling upgradeable smart contract patterns. Delegates calls to an implementation contract.
Blockchain: Ethereum
Source Code: View Code On The Blockchain
Solidity Source Code:
{{
"language": "Solidity",
"sources": {
"@openzeppelin/contracts/utils/Arrays.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (utils/Arrays.sol)
// This file was procedurally generated from scripts/generate/templates/Arrays.js.
pragma solidity ^0.8.20;
import {Comparators} from "./Comparators.sol";
import {SlotDerivation} from "./SlotDerivation.sol";
import {StorageSlot} from "./StorageSlot.sol";
import {Math} from "./math/Math.sol";
/**
* @dev Collection of functions related to array types.
*/
library Arrays {
using SlotDerivation for bytes32;
using StorageSlot for bytes32;
/**
* @dev Sort an array of uint256 (in memory) following the provided comparator function.
*
* This function does the sorting "in place", meaning that it overrides the input. The object is returned for
* convenience, but that returned value can be discarded safely if the caller has a memory pointer to the array.
*
* NOTE: this function's cost is `O(n · log(n))` in average and `O(n²)` in the worst case, with n the length of the
* array. Using it in view functions that are executed through `eth_call` is safe, but one should be very careful
* when executing this as part of a transaction. If the array being sorted is too large, the sort operation may
* consume more gas than is available in a block, leading to potential DoS.
*
* IMPORTANT: Consider memory side-effects when using custom comparator functions that access memory in an unsafe way.
*/
function sort(
uint256[] memory array,
function(uint256, uint256) pure returns (bool) comp
) internal pure returns (uint256[] memory) {
_quickSort(_begin(array), _end(array), comp);
return array;
}
/**
* @dev Variant of {sort} that sorts an array of uint256 in increasing order.
*/
function sort(uint256[] memory array) internal pure returns (uint256[] memory) {
sort(array, Comparators.lt);
return array;
}
/**
* @dev Sort an array of address (in memory) following the provided comparator function.
*
* This function does the sorting "in place", meaning that it overrides the input. The object is returned for
* convenience, but that returned value can be discarded safely if the caller has a memory pointer to the array.
*
* NOTE: this function's cost is `O(n · log(n))` in average and `O(n²)` in the worst case, with n the length of the
* array. Using it in view functions that are executed through `eth_call` is safe, but one should be very careful
* when executing this as part of a transaction. If the array being sorted is too large, the sort operation may
* consume more gas than is available in a block, leading to potential DoS.
*
* IMPORTANT: Consider memory side-effects when using custom comparator functions that access memory in an unsafe way.
*/
function sort(
address[] memory array,
function(address, address) pure returns (bool) comp
) internal pure returns (address[] memory) {
sort(_castToUint256Array(array), _castToUint256Comp(comp));
return array;
}
/**
* @dev Variant of {sort} that sorts an array of address in increasing order.
*/
function sort(address[] memory array) internal pure returns (address[] memory) {
sort(_castToUint256Array(array), Comparators.lt);
return array;
}
/**
* @dev Sort an array of bytes32 (in memory) following the provided comparator function.
*
* This function does the sorting "in place", meaning that it overrides the input. The object is returned for
* convenience, but that returned value can be discarded safely if the caller has a memory pointer to the array.
*
* NOTE: this function's cost is `O(n · log(n))` in average and `O(n²)` in the worst case, with n the length of the
* array. Using it in view functions that are executed through `eth_call` is safe, but one should be very careful
* when executing this as part of a transaction. If the array being sorted is too large, the sort operation may
* consume more gas than is available in a block, leading to potential DoS.
*
* IMPORTANT: Consider memory side-effects when using custom comparator functions that access memory in an unsafe way.
*/
function sort(
bytes32[] memory array,
function(bytes32, bytes32) pure returns (bool) comp
) internal pure returns (bytes32[] memory) {
sort(_castToUint256Array(array), _castToUint256Comp(comp));
return array;
}
/**
* @dev Variant of {sort} that sorts an array of bytes32 in increasing order.
*/
function sort(bytes32[] memory array) internal pure returns (bytes32[] memory) {
sort(_castToUint256Array(array), Comparators.lt);
return array;
}
/**
* @dev Performs a quick sort of a segment of memory. The segment sorted starts at `begin` (inclusive), and stops
* at end (exclusive). Sorting follows the `comp` comparator.
*
* Invariant: `begin <= end`. This is the case when initially called by {sort} and is preserved in subcalls.
*
* IMPORTANT: Memory locations between `begin` and `end` are not validated/zeroed. This function should
* be used only if the limits are within a memory array.
*/
function _quickSort(uint256 begin, uint256 end, function(uint256, uint256) pure returns (bool) comp) private pure {
unchecked {
if (end - begin < 0x40) return;
// Use first element as pivot
uint256 pivot = _mload(begin);
// Position where the pivot should be at the end of the loop
uint256 pos = begin;
for (uint256 it = begin + 0x20; it < end; it += 0x20) {
if (comp(_mload(it), pivot)) {
// If the value stored at the iterator's position comes before the pivot, we increment the
// position of the pivot and move the value there.
pos += 0x20;
_swap(pos, it);
}
}
_swap(begin, pos); // Swap pivot into place
_quickSort(begin, pos, comp); // Sort the left side of the pivot
_quickSort(pos + 0x20, end, comp); // Sort the right side of the pivot
}
}
/**
* @dev Pointer to the memory location of the first element of `array`.
*/
function _begin(uint256[] memory array) private pure returns (uint256 ptr) {
assembly ("memory-safe") {
ptr := add(array, 0x20)
}
}
/**
* @dev Pointer to the memory location of the first memory word (32bytes) after `array`. This is the memory word
* that comes just after the last element of the array.
*/
function _end(uint256[] memory array) private pure returns (uint256 ptr) {
unchecked {
return _begin(array) + array.length * 0x20;
}
}
/**
* @dev Load memory word (as a uint256) at location `ptr`.
*/
function _mload(uint256 ptr) private pure returns (uint256 value) {
assembly {
value := mload(ptr)
}
}
/**
* @dev Swaps the elements memory location `ptr1` and `ptr2`.
*/
function _swap(uint256 ptr1, uint256 ptr2) private pure {
assembly {
let value1 := mload(ptr1)
let value2 := mload(ptr2)
mstore(ptr1, value2)
mstore(ptr2, value1)
}
}
/// @dev Helper: low level cast address memory array to uint256 memory array
function _castToUint256Array(address[] memory input) private pure returns (uint256[] memory output) {
assembly {
output := input
}
}
/// @dev Helper: low level cast bytes32 memory array to uint256 memory array
function _castToUint256Array(bytes32[] memory input) private pure returns (uint256[] memory output) {
assembly {
output := input
}
}
/// @dev Helper: low level cast address comp function to uint256 comp function
function _castToUint256Comp(
function(address, address) pure returns (bool) input
) private pure returns (function(uint256, uint256) pure returns (bool) output) {
assembly {
output := input
}
}
/// @dev Helper: low level cast bytes32 comp function to uint256 comp function
function _castToUint256Comp(
function(bytes32, bytes32) pure returns (bool) input
) private pure returns (function(uint256, uint256) pure returns (bool) output) {
assembly {
output := input
}
}
/**
* @dev Searches a sorted `array` and returns the first index that contains
* a value greater or equal to `element`. If no such index exists (i.e. all
* values in the array are strictly less than `element`), the array length is
* returned. Time complexity O(log n).
*
* NOTE: The `array` is expected to be sorted in ascending order, and to
* contain no repeated elements.
*
* IMPORTANT: Deprecated. This implementation behaves as {lowerBound} but lacks
* support for repeated elements in the array. The {lowerBound} function should
* be used instead.
*/
function findUpperBound(uint256[] storage array, uint256 element) internal view returns (uint256) {
uint256 low = 0;
uint256 high = array.length;
if (high == 0) {
return 0;
}
while (low < high) {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeAccess(array, mid).value > element) {
high = mid;
} else {
low = mid + 1;
}
}
// At this point `low` is the exclusive upper bound. We will return the inclusive upper bound.
if (low > 0 && unsafeAccess(array, low - 1).value == element) {
return low - 1;
} else {
return low;
}
}
/**
* @dev Searches an `array` sorted in ascending order and returns the first
* index that contains a value greater or equal than `element`. If no such index
* exists (i.e. all values in the array are strictly less than `element`), the array
* length is returned. Time complexity O(log n).
*
* See C++'s https://en.cppreference.com/w/cpp/algorithm/lower_bound[lower_bound].
*/
function lowerBound(uint256[] storage array, uint256 element) internal view returns (uint256) {
uint256 low = 0;
uint256 high = array.length;
if (high == 0) {
return 0;
}
while (low < high) {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeAccess(array, mid).value < element) {
// this cannot overflow because mid < high
unchecked {
low = mid + 1;
}
} else {
high = mid;
}
}
return low;
}
/**
* @dev Searches an `array` sorted in ascending order and returns the first
* index that contains a value strictly greater than `element`. If no such index
* exists (i.e. all values in the array are strictly less than `element`), the array
* length is returned. Time complexity O(log n).
*
* See C++'s https://en.cppreference.com/w/cpp/algorithm/upper_bound[upper_bound].
*/
function upperBound(uint256[] storage array, uint256 element) internal view returns (uint256) {
uint256 low = 0;
uint256 high = array.length;
if (high == 0) {
return 0;
}
while (low < high) {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeAccess(array, mid).value > element) {
high = mid;
} else {
// this cannot overflow because mid < high
unchecked {
low = mid + 1;
}
}
}
return low;
}
/**
* @dev Same as {lowerBound}, but with an array in memory.
*/
function lowerBoundMemory(uint256[] memory array, uint256 element) internal pure returns (uint256) {
uint256 low = 0;
uint256 high = array.length;
if (high == 0) {
return 0;
}
while (low < high) {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeMemoryAccess(array, mid) < element) {
// this cannot overflow because mid < high
unchecked {
low = mid + 1;
}
} else {
high = mid;
}
}
return low;
}
/**
* @dev Same as {upperBound}, but with an array in memory.
*/
function upperBoundMemory(uint256[] memory array, uint256 element) internal pure returns (uint256) {
uint256 low = 0;
uint256 high = array.length;
if (high == 0) {
return 0;
}
while (low < high) {
uint256 mid = Math.average(low, high);
// Note that mid will always be strictly less than high (i.e. it will be a valid array index)
// because Math.average rounds towards zero (it does integer division with truncation).
if (unsafeMemoryAccess(array, mid) > element) {
high = mid;
} else {
// this cannot overflow because mid < high
unchecked {
low = mid + 1;
}
}
}
return low;
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeAccess(address[] storage arr, uint256 pos) internal pure returns (StorageSlot.AddressSlot storage) {
bytes32 slot;
assembly ("memory-safe") {
slot := arr.slot
}
return slot.deriveArray().offset(pos).getAddressSlot();
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeAccess(bytes32[] storage arr, uint256 pos) internal pure returns (StorageSlot.Bytes32Slot storage) {
bytes32 slot;
assembly ("memory-safe") {
slot := arr.slot
}
return slot.deriveArray().offset(pos).getBytes32Slot();
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeAccess(uint256[] storage arr, uint256 pos) internal pure returns (StorageSlot.Uint256Slot storage) {
bytes32 slot;
assembly ("memory-safe") {
slot := arr.slot
}
return slot.deriveArray().offset(pos).getUint256Slot();
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeMemoryAccess(address[] memory arr, uint256 pos) internal pure returns (address res) {
assembly {
res := mload(add(add(arr, 0x20), mul(pos, 0x20)))
}
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeMemoryAccess(bytes32[] memory arr, uint256 pos) internal pure returns (bytes32 res) {
assembly {
res := mload(add(add(arr, 0x20), mul(pos, 0x20)))
}
}
/**
* @dev Access an array in an "unsafe" way. Skips solidity "index-out-of-range" check.
*
* WARNING: Only use if you are certain `pos` is lower than the array length.
*/
function unsafeMemoryAccess(uint256[] memory arr, uint256 pos) internal pure returns (uint256 res) {
assembly {
res := mload(add(add(arr, 0x20), mul(pos, 0x20)))
}
}
/**
* @dev Helper to set the length of a dynamic array. Directly writing to `.length` is forbidden.
*
* WARNING: this does not clear elements if length is reduced, of initialize elements if length is increased.
*/
function unsafeSetLength(address[] storage array, uint256 len) internal {
assembly ("memory-safe") {
sstore(array.slot, len)
}
}
/**
* @dev Helper to set the length of a dynamic array. Directly writing to `.length` is forbidden.
*
* WARNING: this does not clear elements if length is reduced, of initialize elements if length is increased.
*/
function unsafeSetLength(bytes32[] storage array, uint256 len) internal {
assembly ("memory-safe") {
sstore(array.slot, len)
}
}
/**
* @dev Helper to set the length of a dynamic array. Directly writing to `.length` is forbidden.
*
* WARNING: this does not clear elements if length is reduced, of initialize elements if length is increased.
*/
function unsafeSetLength(uint256[] storage array, uint256 len) internal {
assembly ("memory-safe") {
sstore(array.slot, len)
}
}
}
"
},
"@openzeppelin/contracts/utils/Comparators.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/Comparators.sol)
pragma solidity ^0.8.20;
/**
* @dev Provides a set of functions to compare values.
*
* _Available since v5.1._
*/
library Comparators {
function lt(uint256 a, uint256 b) internal pure returns (bool) {
return a < b;
}
function gt(uint256 a, uint256 b) internal pure returns (bool) {
return a > b;
}
}
"
},
"@openzeppelin/contracts/utils/introspection/ERC165Checker.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/introspection/ERC165Checker.sol)
pragma solidity ^0.8.20;
import {IERC165} from "./IERC165.sol";
/**
* @dev Library used to query support of an interface declared via {IERC165}.
*
* Note that these functions return the actual result of the query: they do not
* `revert` if an interface is not supported. It is up to the caller to decide
* what to do in these cases.
*/
library ERC165Checker {
// As per the ERC-165 spec, no interface should ever match 0xffffffff
bytes4 private constant INTERFACE_ID_INVALID = 0xffffffff;
/**
* @dev Returns true if `account` supports the {IERC165} interface.
*/
function supportsERC165(address account) internal view returns (bool) {
// Any contract that implements ERC-165 must explicitly indicate support of
// InterfaceId_ERC165 and explicitly indicate non-support of InterfaceId_Invalid
return
supportsERC165InterfaceUnchecked(account, type(IERC165).interfaceId) &&
!supportsERC165InterfaceUnchecked(account, INTERFACE_ID_INVALID);
}
/**
* @dev Returns true if `account` supports the interface defined by
* `interfaceId`. Support for {IERC165} itself is queried automatically.
*
* See {IERC165-supportsInterface}.
*/
function supportsInterface(address account, bytes4 interfaceId) internal view returns (bool) {
// query support of both ERC-165 as per the spec and support of _interfaceId
return supportsERC165(account) && supportsERC165InterfaceUnchecked(account, interfaceId);
}
/**
* @dev Returns a boolean array where each value corresponds to the
* interfaces passed in and whether they're supported or not. This allows
* you to batch check interfaces for a contract where your expectation
* is that some interfaces may not be supported.
*
* See {IERC165-supportsInterface}.
*/
function getSupportedInterfaces(
address account,
bytes4[] memory interfaceIds
) internal view returns (bool[] memory) {
// an array of booleans corresponding to interfaceIds and whether they're supported or not
bool[] memory interfaceIdsSupported = new bool[](interfaceIds.length);
// query support of ERC-165 itself
if (supportsERC165(account)) {
// query support of each interface in interfaceIds
for (uint256 i = 0; i < interfaceIds.length; i++) {
interfaceIdsSupported[i] = supportsERC165InterfaceUnchecked(account, interfaceIds[i]);
}
}
return interfaceIdsSupported;
}
/**
* @dev Returns true if `account` supports all the interfaces defined in
* `interfaceIds`. Support for {IERC165} itself is queried automatically.
*
* Batch-querying can lead to gas savings by skipping repeated checks for
* {IERC165} support.
*
* See {IERC165-supportsInterface}.
*/
function supportsAllInterfaces(address account, bytes4[] memory interfaceIds) internal view returns (bool) {
// query support of ERC-165 itself
if (!supportsERC165(account)) {
return false;
}
// query support of each interface in interfaceIds
for (uint256 i = 0; i < interfaceIds.length; i++) {
if (!supportsERC165InterfaceUnchecked(account, interfaceIds[i])) {
return false;
}
}
// all interfaces supported
return true;
}
/**
* @notice Query if a contract implements an interface, does not check ERC-165 support
* @param account The address of the contract to query for support of an interface
* @param interfaceId The interface identifier, as specified in ERC-165
* @return true if the contract at account indicates support of the interface with
* identifier interfaceId, false otherwise
* @dev Assumes that account contains a contract that supports ERC-165, otherwise
* the behavior of this method is undefined. This precondition can be checked
* with {supportsERC165}.
*
* Some precompiled contracts will falsely indicate support for a given interface, so caution
* should be exercised when using this function.
*
* Interface identification is specified in ERC-165.
*/
function supportsERC165InterfaceUnchecked(address account, bytes4 interfaceId) internal view returns (bool) {
// prepare call
bytes memory encodedParams = abi.encodeCall(IERC165.supportsInterface, (interfaceId));
// perform static call
bool success;
uint256 returnSize;
uint256 returnValue;
assembly ("memory-safe") {
success := staticcall(30000, account, add(encodedParams, 0x20), mload(encodedParams), 0x00, 0x20)
returnSize := returndatasize()
returnValue := mload(0x00)
}
return success && returnSize >= 0x20 && returnValue > 0;
}
}
"
},
"@openzeppelin/contracts/utils/introspection/IERC165.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/introspection/IERC165.sol)
pragma solidity ^0.8.20;
/**
* @dev Interface of the ERC-165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[ERC].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
"
},
"@openzeppelin/contracts/utils/math/Math.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (utils/math/Math.sol)
pragma solidity ^0.8.20;
import {Panic} from "../Panic.sol";
import {SafeCast} from "./SafeCast.sol";
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Floor, // Toward negative infinity
Ceil, // Toward positive infinity
Trunc, // Toward zero
Expand // Away from zero
}
/**
* @dev Return the 512-bit addition of two uint256.
*
* The result is stored in two 256 variables such that sum = high * 2²⁵⁶ + low.
*/
function add512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
assembly ("memory-safe") {
low := add(a, b)
high := lt(low, a)
}
}
/**
* @dev Return the 512-bit multiplication of two uint256.
*
* The result is stored in two 256 variables such that product = high * 2²⁵⁶ + low.
*/
function mul512(uint256 a, uint256 b) internal pure returns (uint256 high, uint256 low) {
// 512-bit multiply [high low] = x * y. Compute the product mod 2²⁵⁶ and mod 2²⁵⁶ - 1, then use
// the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = high * 2²⁵⁶ + low.
assembly ("memory-safe") {
let mm := mulmod(a, b, not(0))
low := mul(a, b)
high := sub(sub(mm, low), lt(mm, low))
}
}
/**
* @dev Returns the addition of two unsigned integers, with a success flag (no overflow).
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a + b;
success = c >= a;
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with a success flag (no overflow).
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a - b;
success = c <= a;
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the multiplication of two unsigned integers, with a success flag (no overflow).
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
uint256 c = a * b;
assembly ("memory-safe") {
// Only true when the multiplication doesn't overflow
// (c / a == b) || (a == 0)
success := or(eq(div(c, a), b), iszero(a))
}
// equivalent to: success ? c : 0
result = c * SafeCast.toUint(success);
}
}
/**
* @dev Returns the division of two unsigned integers, with a success flag (no division by zero).
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
success = b > 0;
assembly ("memory-safe") {
// The `DIV` opcode returns zero when the denominator is 0.
result := div(a, b)
}
}
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a success flag (no division by zero).
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool success, uint256 result) {
unchecked {
success = b > 0;
assembly ("memory-safe") {
// The `MOD` opcode returns zero when the denominator is 0.
result := mod(a, b)
}
}
}
/**
* @dev Unsigned saturating addition, bounds to `2²⁵⁶ - 1` instead of overflowing.
*/
function saturatingAdd(uint256 a, uint256 b) internal pure returns (uint256) {
(bool success, uint256 result) = tryAdd(a, b);
return ternary(success, result, type(uint256).max);
}
/**
* @dev Unsigned saturating subtraction, bounds to zero instead of overflowing.
*/
function saturatingSub(uint256 a, uint256 b) internal pure returns (uint256) {
(, uint256 result) = trySub(a, b);
return result;
}
/**
* @dev Unsigned saturating multiplication, bounds to `2²⁵⁶ - 1` instead of overflowing.
*/
function saturatingMul(uint256 a, uint256 b) internal pure returns (uint256) {
(bool success, uint256 result) = tryMul(a, b);
return ternary(success, result, type(uint256).max);
}
/**
* @dev Branchless ternary evaluation for `a ? b : c`. Gas costs are constant.
*
* IMPORTANT: This function may reduce bytecode size and consume less gas when used standalone.
* However, the compiler may optimize Solidity ternary operations (i.e. `a ? b : c`) to only compute
* one branch when needed, making this function more expensive.
*/
function ternary(bool condition, uint256 a, uint256 b) internal pure returns (uint256) {
unchecked {
// branchless ternary works because:
// b ^ (a ^ b) == a
// b ^ 0 == b
return b ^ ((a ^ b) * SafeCast.toUint(condition));
}
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return ternary(a > b, a, b);
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return ternary(a < b, a, b);
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds towards infinity instead
* of rounding towards zero.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
if (b == 0) {
// Guarantee the same behavior as in a regular Solidity division.
Panic.panic(Panic.DIVISION_BY_ZERO);
}
// The following calculation ensures accurate ceiling division without overflow.
// Since a is non-zero, (a - 1) / b will not overflow.
// The largest possible result occurs when (a - 1) / b is type(uint256).max,
// but the largest value we can obtain is type(uint256).max - 1, which happens
// when a = type(uint256).max and b = 1.
unchecked {
return SafeCast.toUint(a > 0) * ((a - 1) / b + 1);
}
}
/**
* @dev Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or
* denominator == 0.
*
* Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv) with further edits by
* Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
(uint256 high, uint256 low) = mul512(x, y);
// Handle non-overflow cases, 256 by 256 division.
if (high == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return low / denominator;
}
// Make sure the result is less than 2²⁵⁶. Also prevents denominator == 0.
if (denominator <= high) {
Panic.panic(ternary(denominator == 0, Panic.DIVISION_BY_ZERO, Panic.UNDER_OVERFLOW));
}
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [high low].
uint256 remainder;
assembly ("memory-safe") {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
high := sub(high, gt(remainder, low))
low := sub(low, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator.
// Always >= 1. See https://cs.stackexchange.com/q/138556/92363.
uint256 twos = denominator & (0 - denominator);
assembly ("memory-safe") {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [high low] by twos.
low := div(low, twos)
// Flip twos such that it is 2²⁵⁶ / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from high into low.
low |= high * twos;
// Invert denominator mod 2²⁵⁶. Now that denominator is an odd number, it has an inverse modulo 2²⁵⁶ such
// that denominator * inv ≡ 1 mod 2²⁵⁶. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv ≡ 1 mod 2⁴.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also
// works in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2⁸
inverse *= 2 - denominator * inverse; // inverse mod 2¹⁶
inverse *= 2 - denominator * inverse; // inverse mod 2³²
inverse *= 2 - denominator * inverse; // inverse mod 2⁶⁴
inverse *= 2 - denominator * inverse; // inverse mod 2¹²⁸
inverse *= 2 - denominator * inverse; // inverse mod 2²⁵⁶
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2²⁵⁶. Since the preconditions guarantee that the outcome is
// less than 2²⁵⁶, this is the final result. We don't need to compute the high bits of the result and high
// is no longer required.
result = low * inverse;
return result;
}
}
/**
* @dev Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
return mulDiv(x, y, denominator) + SafeCast.toUint(unsignedRoundsUp(rounding) && mulmod(x, y, denominator) > 0);
}
/**
* @dev Calculates floor(x * y >> n) with full precision. Throws if result overflows a uint256.
*/
function mulShr(uint256 x, uint256 y, uint8 n) internal pure returns (uint256 result) {
unchecked {
(uint256 high, uint256 low) = mul512(x, y);
if (high >= 1 << n) {
Panic.panic(Panic.UNDER_OVERFLOW);
}
return (high << (256 - n)) | (low >> n);
}
}
/**
* @dev Calculates x * y >> n with full precision, following the selected rounding direction.
*/
function mulShr(uint256 x, uint256 y, uint8 n, Rounding rounding) internal pure returns (uint256) {
return mulShr(x, y, n) + SafeCast.toUint(unsignedRoundsUp(rounding) && mulmod(x, y, 1 << n) > 0);
}
/**
* @dev Calculate the modular multiplicative inverse of a number in Z/nZ.
*
* If n is a prime, then Z/nZ is a field. In that case all elements are inversible, except 0.
* If n is not a prime, then Z/nZ is not a field, and some elements might not be inversible.
*
* If the input value is not inversible, 0 is returned.
*
* NOTE: If you know for sure that n is (big) a prime, it may be cheaper to use Fermat's little theorem and get the
* inverse using `Math.modExp(a, n - 2, n)`. See {invModPrime}.
*/
function invMod(uint256 a, uint256 n) internal pure returns (uint256) {
unchecked {
if (n == 0) return 0;
// The inverse modulo is calculated using the Extended Euclidean Algorithm (iterative version)
// Used to compute integers x and y such that: ax + ny = gcd(a, n).
// When the gcd is 1, then the inverse of a modulo n exists and it's x.
// ax + ny = 1
// ax = 1 + (-y)n
// ax ≡ 1 (mod n) # x is the inverse of a modulo n
// If the remainder is 0 the gcd is n right away.
uint256 remainder = a % n;
uint256 gcd = n;
// Therefore the initial coefficients are:
// ax + ny = gcd(a, n) = n
// 0a + 1n = n
int256 x = 0;
int256 y = 1;
while (remainder != 0) {
uint256 quotient = gcd / remainder;
(gcd, remainder) = (
// The old remainder is the next gcd to try.
remainder,
// Compute the next remainder.
// Can't overflow given that (a % gcd) * (gcd // (a % gcd)) <= gcd
// where gcd is at most n (capped to type(uint256).max)
gcd - remainder * quotient
);
(x, y) = (
// Increment the coefficient of a.
y,
// Decrement the coefficient of n.
// Can overflow, but the result is casted to uint256 so that the
// next value of y is "wrapped around" to a value between 0 and n - 1.
x - y * int256(quotient)
);
}
if (gcd != 1) return 0; // No inverse exists.
return ternary(x < 0, n - uint256(-x), uint256(x)); // Wrap the result if it's negative.
}
}
/**
* @dev Variant of {invMod}. More efficient, but only works if `p` is known to be a prime greater than `2`.
*
* From https://en.wikipedia.org/wiki/Fermat%27s_little_theorem[Fermat's little theorem], we know that if p is
* prime, then `a**(p-1) ≡ 1 mod p`. As a consequence, we have `a * a**(p-2) ≡ 1 mod p`, which means that
* `a**(p-2)` is the modular multiplicative inverse of a in Fp.
*
* NOTE: this function does NOT check that `p` is a prime greater than `2`.
*/
function invModPrime(uint256 a, uint256 p) internal view returns (uint256) {
unchecked {
return Math.modExp(a, p - 2, p);
}
}
/**
* @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m)
*
* Requirements:
* - modulus can't be zero
* - underlying staticcall to precompile must succeed
*
* IMPORTANT: The result is only valid if the underlying call succeeds. When using this function, make
* sure the chain you're using it on supports the precompiled contract for modular exponentiation
* at address 0x05 as specified in https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise,
* the underlying function will succeed given the lack of a revert, but the result may be incorrectly
* interpreted as 0.
*/
function modExp(uint256 b, uint256 e, uint256 m) internal view returns (uint256) {
(bool success, uint256 result) = tryModExp(b, e, m);
if (!success) {
Panic.panic(Panic.DIVISION_BY_ZERO);
}
return result;
}
/**
* @dev Returns the modular exponentiation of the specified base, exponent and modulus (b ** e % m).
* It includes a success flag indicating if the operation succeeded. Operation will be marked as failed if trying
* to operate modulo 0 or if the underlying precompile reverted.
*
* IMPORTANT: The result is only valid if the success flag is true. When using this function, make sure the chain
* you're using it on supports the precompiled contract for modular exponentiation at address 0x05 as specified in
* https://eips.ethereum.org/EIPS/eip-198[EIP-198]. Otherwise, the underlying function will succeed given the lack
* of a revert, but the result may be incorrectly interpreted as 0.
*/
function tryModExp(uint256 b, uint256 e, uint256 m) internal view returns (bool success, uint256 result) {
if (m == 0) return (false, 0);
assembly ("memory-safe") {
let ptr := mload(0x40)
// | Offset | Content | Content (Hex) |
// |-----------|------------|--------------------------------------------------------------------|
// | 0x00:0x1f | size of b | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x20:0x3f | size of e | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x40:0x5f | size of m | 0x0000000000000000000000000000000000000000000000000000000000000020 |
// | 0x60:0x7f | value of b | 0x<.............................................................b> |
// | 0x80:0x9f | value of e | 0x<.............................................................e> |
// | 0xa0:0xbf | value of m | 0x<.............................................................m> |
mstore(ptr, 0x20)
mstore(add(ptr, 0x20), 0x20)
mstore(add(ptr, 0x40), 0x20)
mstore(add(ptr, 0x60), b)
mstore(add(ptr, 0x80), e)
mstore(add(ptr, 0xa0), m)
// Given the result < m, it's guaranteed to fit in 32 bytes,
// so we can use the memory scratch space located at offset 0.
success := staticcall(gas(), 0x05, ptr, 0xc0, 0x00, 0x20)
result := mload(0x00)
}
}
/**
* @dev Variant of {modExp} that supports inputs of arbitrary length.
*/
function modExp(bytes memory b, bytes memory e, bytes memory m) internal view returns (bytes memory) {
(bool success, bytes memory result) = tryModExp(b, e, m);
if (!success) {
Panic.panic(Panic.DIVISION_BY_ZERO);
}
return result;
}
/**
* @dev Variant of {tryModExp} that supports inputs of arbitrary length.
*/
function tryModExp(
bytes memory b,
bytes memory e,
bytes memory m
) internal view returns (bool success, bytes memory result) {
if (_zeroBytes(m)) return (false, new bytes(0));
uint256 mLen = m.length;
// Encode call args in result and move the free memory pointer
result = abi.encodePacked(b.length, e.length, mLen, b, e, m);
assembly ("memory-safe") {
let dataPtr := add(result, 0x20)
// Write result on top of args to avoid allocating extra memory.
success := staticcall(gas(), 0x05, dataPtr, mload(result), dataPtr, mLen)
// Overwrite the length.
// result.length > returndatasize() is guaranteed because returndatasize() == m.length
mstore(result, mLen)
// Set the memory pointer after the returned data.
mstore(0x40, add(dataPtr, mLen))
}
}
/**
* @dev Returns whether the provided byte array is zero.
*/
function _zeroBytes(bytes memory byteArray) private pure returns (bool) {
for (uint256 i = 0; i < byteArray.length; ++i) {
if (byteArray[i] != 0) {
return false;
}
}
return true;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded
* towards zero.
*
* This method is based on Newton's method for computing square roots; the algorithm is restricted to only
* using integer operations.
*/
function sqrt(uint256 a) internal pure returns (uint256) {
unchecked {
// Take care of easy edge cases when a == 0 or a == 1
if (a <= 1) {
return a;
}
// In this function, we use Newton's method to get a root of `f(x) := x² - a`. It involves building a
// sequence x_n that converges toward sqrt(a). For each iteration x_n, we also define the error between
// the current value as `ε_n = | x_n - sqrt(a) |`.
//
// For our first estimation, we consider `e` the smallest power of 2 which is bigger than the square root
// of the target. (i.e. `2**(e-1) ≤ sqrt(a) < 2**e`). We know that `e ≤ 128` because `(2¹²⁸)² = 2²⁵⁶` is
// bigger than any uint256.
//
// By noticing that
// `2**(e-1) ≤ sqrt(a) < 2**e → (2**(e-1))² ≤ a < (2**e)² → 2**(2*e-2) ≤ a < 2**(2*e)`
// we can deduce that `e - 1` is `log2(a) / 2`. We can thus compute `x_n = 2**(e-1)` using a method similar
// to the msb function.
uint256 aa = a;
uint256 xn = 1;
if (aa >= (1 << 128)) {
aa >>= 128;
xn <<= 64;
}
if (aa >= (1 << 64)) {
aa >>= 64;
xn <<= 32;
}
if (aa >= (1 << 32)) {
aa >>= 32;
xn <<= 16;
}
if (aa >= (1 << 16)) {
aa >>= 16;
xn <<= 8;
}
if (aa >= (1 << 8)) {
aa >>= 8;
xn <<= 4;
}
if (aa >= (1 << 4)) {
aa >>= 4;
xn <<= 2;
}
if (aa >= (1 << 2)) {
xn <<= 1;
}
// We now have x_n such that `x_n = 2**(e-1) ≤ sqrt(a) < 2**e = 2 * x_n`. This implies ε_n ≤ 2**(e-1).
//
// We can refine our estimation by noticing that the middle of that interval minimizes the error.
// If we move x_n to equal 2**(e-1) + 2**(e-2), then we reduce the error to ε_n ≤ 2**(e-2).
// This is going to be our x_0 (and ε_0)
xn = (3 * xn) >> 1; // ε_0 := | x_0 - sqrt(a) | ≤ 2**(e-2)
// From here, Newton's method give us:
// x_{n+1} = (x_n + a / x_n) / 2
//
// One should note that:
// x_{n+1}² - a = ((x_n + a / x_n) / 2)² - a
// = ((x_n² + a) / (2 * x_n))² - a
// = (x_n⁴ + 2 * a * x_n² + a²) / (4 * x_n²) - a
// = (x_n⁴ + 2 * a * x_n² + a² - 4 * a * x_n²) / (4 * x_n²)
// = (x_n⁴ - 2 * a * x_n² + a²) / (4 * x_n²)
// = (x_n² - a)² / (2 * x_n)²
// = ((x_n² - a) / (2 * x_n))²
// ≥ 0
// Which proves that for all n ≥ 1, sqrt(a) ≤ x_n
//
// This gives us the proof of quadratic convergence of the sequence:
// ε_{n+1} = | x_{n+1} - sqrt(a) |
// = | (x_n + a / x_n) / 2 - sqrt(a) |
// = | (x_n² + a - 2*x_n*sqrt(a)) / (2 * x_n) |
// = | (x_n - sqrt(a))² / (2 * x_n) |
// = | ε_n² / (2 * x_n) |
// = ε_n² / | (2 * x_n) |
//
// For the first iteration, we have a special case where x_0 is known:
// ε_1 = ε_0² / | (2 * x_0) |
// ≤ (2**(e-2))² / (2 * (2**(e-1) + 2**(e-2)))
// ≤ 2**(2*e-4) / (3 * 2**(e-1))
// ≤ 2**(e-3) / 3
// ≤ 2**(e-3-log2(3))
// ≤ 2**(e-4.5)
//
// For the following iterations, we use the fact that, 2**(e-1) ≤ sqrt(a) ≤ x_n:
// ε_{n+1} = ε_n² / | (2 * x_n) |
// ≤ (2**(e-k))² / (2 * 2**(e-1))
// ≤ 2**(2*e-2*k) / 2**e
// ≤ 2**(e-2*k)
xn = (xn + a / xn) >> 1; // ε_1 := | x_1 - sqrt(a) | ≤ 2**(e-4.5) -- special case, see above
xn = (xn + a / xn) >> 1; // ε_2 := | x_2 - sqrt(a) | ≤ 2**(e-9) -- general case with k = 4.5
xn = (xn + a / xn) >> 1; // ε_3 := | x_3 - sqrt(a) | ≤ 2**(e-18) -- general case with k = 9
xn = (xn + a / xn) >> 1; // ε_4 := | x_4 - sqrt(a) | ≤ 2**(e-36) -- general case with k = 18
xn = (xn + a / xn) >> 1; // ε_5 := | x_5 - sqrt(a) | ≤ 2**(e-72) -- general case with k = 36
xn = (xn + a / xn) >> 1; // ε_6 := | x_6 - sqrt(a) | ≤ 2**(e-144) -- general case with k = 72
// Because e ≤ 128 (as discussed during the first estimation phase), we know have reached a precision
// ε_6 ≤ 2**(e-144) < 1. Given we're operating on integers, then we can ensure that xn is now either
// sqrt(a) or sqrt(a) + 1.
return xn - SafeCast.toUint(xn > a / xn);
}
}
/**
* @dev Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && result * result < a);
}
}
/**
* @dev Return the log in base 2 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log2(uint256 x) internal pure returns (uint256 r) {
// If value has upper 128 bits set, log2 result is at least 128
r = SafeCast.toUint(x > 0xffffffffffffffffffffffffffffffff) << 7;
// If upper 64 bits of 128-bit half set, add 64 to result
r |= SafeCast.toUint((x >> r) > 0xffffffffffffffff) << 6;
// If upper 32 bits of 64-bit half set, add 32 to result
r |= SafeCast.toUint((x >> r) > 0xffffffff) << 5;
// If upper 16 bits of 32-bit half set, add 16 to result
r |= SafeCast.toUint((x >> r) > 0xffff) << 4;
// If upper 8 bits of 16-bit half set, add 8 to result
r |= SafeCast.toUint((x >> r) > 0xff) << 3;
// If upper 4 bits of 8-bit half set, add 4 to result
r |= SafeCast.toUint((x >> r) > 0xf) << 2;
// Shifts value right by the current result and use it as an index into this lookup table:
//
// | x (4 bits) | index | table[index] = MSB position |
// |------------|---------|-----------------------------|
// | 0000 | 0 | table[0] = 0 |
// | 0001 | 1 | table[1] = 0 |
// | 0010 | 2 | table[2] = 1 |
// | 0011 | 3 | table[3] = 1 |
// | 0100 | 4 | table[4] = 2 |
// | 0101 | 5 | table[5] = 2 |
// | 0110 | 6 | table[6] = 2 |
// | 0111 | 7 | table[7] = 2 |
// | 1000 | 8 | table[8] = 3 |
// | 1001 | 9 | table[9] = 3 |
// | 1010 | 10 | table[10] = 3 |
// | 1011 | 11 | table[11] = 3 |
// | 1100 | 12 | table[12] = 3 |
// | 1101 | 13 | table[13] = 3 |
// | 1110 | 14 | table[14] = 3 |
// | 1111 | 15 | table[15] = 3 |
//
// The lookup table is represented as a 32-byte value with the MSB positions for 0-15 in the last 16 bytes.
assembly ("memory-safe") {
r := or(r, byte(shr(r, x), 0x0000010102020202030303030303030300000000000000000000000000000000))
}
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << result < value);
}
}
/**
* @dev Return the log in base 10 of a positive value rounded towards zero.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 10 ** result < value);
}
}
/**
* @dev Return the log in base 256 of a positive value rounded towards zero.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 x) internal pure returns (uint256 r) {
// If value has upper 128 bits set, log2 result is at least 128
r = SafeCast.toUint(x > 0xffffffffffffffffffffffffffffffff) << 7;
// If upper 64 bits of 128-bit half set, add 64 to result
r |= SafeCast.toUint((x >> r) > 0xffffffffffffffff) << 6;
// If upper 32 bits of 64-bit half set, add 32 to result
r |= SafeCast.toUint((x >> r) > 0xffffffff) << 5;
// If upper 16 bits of 32-bit half set, add 16 to result
r |= SafeCast.toUint((x >> r) > 0xffff) << 4;
// Add 1 if upper 8 bits of 16-bit half set, and divide accumulated result by 8
return (r >> 3) | SafeCast.toUint((x >> r) > 0xff);
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + SafeCast.toUint(unsignedRoundsUp(rounding) && 1 << (result << 3) < value);
}
}
/**
* @dev Returns whether a provided rounding mode is considered rounding up for unsigned integers.
*/
function unsignedRoundsUp(Rounding rounding) internal pure returns (bool) {
return uint8(rounding) % 2 == 1;
}
}
"
},
"@openzeppelin/contracts/utils/math/SafeCast.sol": {
"content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/math/SafeCast.sol)
// This file was procedurally generated from scripts/generate/templates/SafeCast.js.
pragma solidity ^0.8.20;
/**
* @dev Wrappers over Solidity's uintXX/intXX/bool casting operators with added overflow
* checks.
*
* Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
* easily result in undesired exploitation or bugs, since developers usually
* assume that overflows raise errors. `SafeCast` restores this intuition by
* reverting the transaction when such an operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeCast {
/**
* @dev Value doesn't fit in an uint of `bits` size.
*/
error SafeCastOverflowedUintDowncast(uint8 bits, uint256 value);
/**
* @dev An int value doesn't fit in an uint of `bits` size.
*/
error SafeCastOverflowedIntToUint(int256 value);
/**
* @dev Value doesn't fit in an int of `bits` size.
*/
error SafeCastOverflowedIntDowncast(uint8 bits, int256 value);
/**
* @dev An uint value doesn't fit in an int of `bits` size.
*/
error SafeCastOverflowedUintToInt(uint256 value);
/**
* @dev Returns the downcasted uint248 from uint256, reverting on
* overflow (when the input is greater than largest uint248).
*
* Counterpart to Solidity's `uint248` operator.
*
* Requirements:
*
* - input must fit into 248 bits
*/
function toUint248(uint256 value) internal pure returns (uint248) {
if (value > type(uint248).max) {
revert SafeCastOverflowedUintDowncast(248, value);
}
return uint248(value);
}
/**
* @dev Returns the downcasted uint240 from uint256, reverting on
* overflow (when the input is greater than largest uint240).
*
* Counterpart to Solidity's `uint240` operator.
*
* Requirements:
*
* - input must fit into 240 bits
*/
function toUint240(uint256 value) internal pure returns (uint240) {
if (value > type(uint240).max) {
revert SafeCastOverflowedUintDowncast(240, value);
}
return uint240(value);
}
/**
* @dev Returns the downcasted uint232 from uint256, reverting on
* overflow (when the input is greater than largest uint232).
*
* Counterpart to Solidity's `uint232` operator.
*
* Requirements:
*
* - input must fit into 232 bits
*/
function toUint232(uint256 value) internal pure returns (uint232) {
if (value > type(uint232).max) {
revert SafeCastOverflowedUintDowncast(232, value);
}
return uint232(value);
}
/**
* @dev Returns the downcasted uint224 from uint256, reverting on
* overflow (when the input is greater than largest uint224).
*
* Counterpart to Solidity's `uint224` operator.
*
* Requirements:
*
* - input must fit into 224 bits
*/
function toUint224(uint256 value) internal pure returns (uint224) {
if (value > type(uint224).max) {
revert SafeCastOverflowedUintDowncast(224, value);
}
return uint224(value);
}
/**
* @dev Returns the downcasted uint216 from uint256, reverting on
* overflow (when the input is greater than largest uint216).
*
* Counterpart to Solidity's `uint216` operator.
*
* Requirements:
*
* - input must fit into 216 bits
*/
function toUint216(uint256 value) internal pure returns (uint216) {
if (value > type(uint216).max) {
revert SafeCastOverflowedUintDowncast(216, value);
}
return uint216(value);
}
/**
* @dev Returns the downcasted uint208 from uint256, reverting on
* overflow (when the input is greater than largest uint208).
*
* Counterpart to Solidity's `uint208` operator.
*
* Requirements:
*
* - input must fit into 208 bits
*/
function toUint208(uint256 value) internal pure returns (uint208) {
if (value > type(uint208).max) {
revert SafeCastOverflowedUintDowncast(208, value);
}
return uint208(value);
}
/**
* @dev Returns the downcasted uint200 from uint256, reverting on
* overflow (when the input is greater than largest uint200).
*
* Counterpart to Solidity's `uint200` operator.
*
* Requirements:
*
* - input must fit into 200 bits
*/
function toUint200(uint256 value) internal pure returns (uint200) {
if (value > type(uint200).max) {
revert SafeCastOverflowedUintDowncast(200, value);
}
return uint200(value);
}
/**
* @dev Returns the downcasted uint192 from uint256, reverting on
* overflow (when the input is greater than largest uint192).
*
* Counterpart to Solidity's `uint192` operator.
*
* Requirements:
*
* - input must fit into 192 bits
*/
function toUint192(uint256 value) internal pure returns (uint192) {
if (value > type(uint192).max) {
revert SafeCastOverflowedUintDowncast(192, value);
}
return uint192(value);
}
/**
* @dev Returns the downcasted uint184 from uint256, reverting on
* overflow (when the input is greater than largest uint184).
*
* Counterpart to Solidity's `uint184` operator.
*
* Requirements:
*
* - input must fit into 184 bits
*/
function toUint184(uint256 value) internal pure returns (uint184) {
if (value > type(uint184).max) {
revert SafeCastOverflowedUintDowncast(184, value);
}
return uint184(value);
}
/**
* @dev Returns the downcasted uint176 from uint256, reverting on
* overflow (when the input is greater than largest uint176).
*
* Counterpart to Solidity's `uint176` operator.
*
* Requirements:
*
* - input must fit into 176 bits
*/
function toUint176(uint256 value) internal pure returns (uint176) {
if (value > type(uint176).max) {
revert SafeCastOverflowedUintDowncast(176, value);
}
return uint176(value);
}
Submitted on: 2025-10-19 13:32:31
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