5dfe7215a9
* Initial migration to Solidity 0.6.x - v3.0 first steps (#2063) * Initial migration, missing GSN, 721, 777 and Crowdsales. * Add _beforeTokenOperation and _afterTokenOperation. * Add documentation for hooks. * Add hooks doc * Add missing drafts * Add back ERC721 with hooks * Bring back ERC777 * Notes on hooks * Bring back GSN * Make functions virtual * Make GSN overrides explicit * Fix ERC20Pausable tests * Remove virtual from some view functions * Update linter * Delete examples * Remove unnecessary virtual * Remove roles from Pausable * Remove roles * Remove users of roles * Adapt ERC20 tests * Fix ERC721 tests * Add all ERC721 hooks * Add ERC777 hooks * Fix remaining tests * Bump compiler version * Move 721BurnableMock into mocks directory * Remove _before hooks * Fix tests * Upgrade linter * Put modifiers last * Remove _beforeTokenApproval and _beforeOperatorApproval hooks
53 lines
1.6 KiB
Solidity
53 lines
1.6 KiB
Solidity
pragma solidity ^0.6.0;
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import "./IERC165.sol";
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/**
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* @dev Implementation of the {IERC165} interface.
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*
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* Contracts may inherit from this and call {_registerInterface} to declare
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* their support of an interface.
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*/
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contract ERC165 is IERC165 {
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/*
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* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
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*/
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bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
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/**
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* @dev Mapping of interface ids to whether or not it's supported.
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*/
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mapping(bytes4 => bool) private _supportedInterfaces;
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constructor () internal {
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// Derived contracts need only register support for their own interfaces,
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// we register support for ERC165 itself here
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_registerInterface(_INTERFACE_ID_ERC165);
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}
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/**
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* @dev See {IERC165-supportsInterface}.
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*
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* Time complexity O(1), guaranteed to always use less than 30 000 gas.
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*/
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function supportsInterface(bytes4 interfaceId) external view override returns (bool) {
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return _supportedInterfaces[interfaceId];
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}
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/**
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* @dev Registers the contract as an implementer of the interface defined by
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* `interfaceId`. Support of the actual ERC165 interface is automatic and
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* registering its interface id is not required.
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*
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* See {IERC165-supportsInterface}.
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*
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* Requirements:
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*
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* - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
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*/
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function _registerInterface(bytes4 interfaceId) internal virtual {
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require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
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_supportedInterfaces[interfaceId] = true;
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}
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}
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