mirror of
https://github.com/ethereum/solidity
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37 lines
1.3 KiB
Solidity
37 lines
1.3 KiB
Solidity
interface ERC165 {
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/// @notice Query if a contract implements an interface
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/// @param interfaceID The interface identifier, as specified in ERC-165
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/// @dev Interface identification is specified in ERC-165. This function
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/// uses less than 30,000 gas.
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/// @return `true` if the contract implements `interfaceID` and
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/// `interfaceID` is not 0xffffffff, `false` otherwise
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function supportsInterface(bytes4 interfaceID) external view returns (bool);
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}
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interface Simpson {
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function is2D() external returns (bool);
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function skinColor() external returns (string memory);
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}
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contract Homer is ERC165, Simpson {
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function supportsInterface(bytes4 interfaceID) external view override returns (bool) {
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return
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interfaceID == this.supportsInterface.selector || // ERC165
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interfaceID == this.is2D.selector ^ this.skinColor.selector; // Simpson
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}
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function is2D() external override returns (bool) {
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return true;
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}
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function skinColor() external override returns (string memory) {
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return "yellow";
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}
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}
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// ----
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// supportsInterface(bytes4): left(0x01ffc9a0) -> false
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// supportsInterface(bytes4): left(0x01ffc9a7) -> true
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// supportsInterface(bytes4): left(0x73b6b492) -> true
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// supportsInterface(bytes4): left(0x70b6b492) -> false
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