add burn function to ERC1155Drop (#264)

add  function to ERC1155Drop

Author: kumaryash90

contracts/base/ERC1155Drop.sol

@@ -155,6 +155,54 @@ contract ERC1155Drop is
         return nextTokenIdToLazyMint;
     }
 
+    /*//////////////////////////////////////////////////////////////
+                        Minting/burning logic
+    //////////////////////////////////////////////////////////////*/
+
+    /**
+     *  @notice         Lets an owner or approved operator burn NFTs of the given tokenId.
+     *
+     *  @param _owner   The owner of the NFT to burn.
+     *  @param _tokenId The tokenId of the NFT to burn.
+     *  @param _amount  The amount of the NFT to burn.
+     */
+    function burn(
+        address _owner,
+        uint256 _tokenId,
+        uint256 _amount
+    ) external virtual {
+        address caller = msg.sender;
+
+        require(caller == _owner || isApprovedForAll[_owner][caller], "Unapproved caller");
+        require(balanceOf[_owner][_tokenId] >= _amount, "Not enough tokens owned");
+
+        _burn(_owner, _tokenId, _amount);
+    }
+
+    /**
+     *  @notice         Lets an owner or approved operator burn NFTs of the given tokenIds.
+     *
+     *  @param _owner    The owner of the NFTs to burn.
+     *  @param _tokenIds The tokenIds of the NFTs to burn.
+     *  @param _amounts  The amounts of the NFTs to burn.
+     */
+    function burnBatch(
+        address _owner,
+        uint256[] memory _tokenIds,
+        uint256[] memory _amounts
+    ) external virtual {
+        address caller = msg.sender;
+
+        require(caller == _owner || isApprovedForAll[_owner][caller], "Unapproved caller");
+        require(_tokenIds.length == _amounts.length, "Length mismatch");
+
+        for (uint256 i = 0; i < _tokenIds.length; i += 1) {
+            require(balanceOf[_owner][_tokenIds[i]] >= _amounts[i], "Not enough tokens owned");
+        }
+
+        _burnBatch(_owner, _tokenIds, _amounts);
+    }
+
     /*//////////////////////////////////////////////////////////////
                             ERC165 Logic
     //////////////////////////////////////////////////////////////*/

docs/ERC1155Drop.md

@@ -56,6 +56,42 @@ function balanceOfBatch(address[] accounts, uint256[] ids) external view returns
 |---|---|---|
 | _0 | uint256[] | undefined |
 
+### burn
+
+```solidity
+function burn(address _owner, uint256 _tokenId, uint256 _amount) external nonpayable
+```
+
+Lets an owner or approved operator burn NFTs of the given tokenId.
+
+
+
+#### Parameters
+
+| Name | Type | Description |
+|---|---|---|
+| _owner | address | The owner of the NFT to burn. |
+| _tokenId | uint256 | The tokenId of the NFT to burn. |
+| _amount | uint256 | The amount of the NFT to burn. |
+
+### burnBatch
+
+```solidity
+function burnBatch(address _owner, uint256[] _tokenIds, uint256[] _amounts) external nonpayable
+```
+
+Lets an owner or approved operator burn NFTs of the given tokenIds.
+
+
+
+#### Parameters
+
+| Name | Type | Description |
+|---|---|---|
+| _owner | address | The owner of the NFTs to burn. |
+| _tokenIds | uint256[] | The tokenIds of the NFTs to burn. |
+| _amounts | uint256[] | The amounts of the NFTs to burn. |
+
 ### claim
 
 ```solidity