// SPDX-License-Identifier: MIT

// Vendored from OpenZeppelin contracts with minor modifications:
// - Modified Solidity version
// - Formatted code
// - Shortened revert messages
// - Removed unused methods
// - Convert to `type(*).*` notation
// <https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v3.4.0/contracts/utils/SafeCast.sol>

pragma solidity ^0.7.6;

/**
 * @dev Wrappers over Solidity's uintXX/intXX 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.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: not positive");
        return uint256(value);
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        require(
            value <= uint256(type(int256).max),
            "SafeCast: int256 overflow"
        );
        return int256(value);
    }
}