Update (tested) examples in docs

Author: matheusaaguiar

docs/050-breaking-changes.rst

@@ -501,6 +501,7 @@ New version:
             // To increase clarity, we suggest the use of a library for
             // the conversion (provided after the contract in this example).
             address payable addr = unknownContract.makePayable();
+            // This will report a warning
             require(addr.send(1 ether));
 
             // Since uint32 (4 bytes) is smaller than bytes8 (8 bytes),

docs/common-patterns.rst

@@ -57,6 +57,7 @@ you receive the funds of the person who is now the richest.
             // Remember to zero the pending refund before
             // sending to prevent reentrancy attacks
             pendingWithdrawals[msg.sender] = 0;
+            // This will report a warning
             payable(msg.sender).transfer(amount);
         }
     }
@@ -84,6 +85,7 @@ This is as opposed to the more intuitive sending pattern:
         function becomeRichest() public payable {
             if (msg.value <= mostSent) revert NotEnoughEther();
             // This line can cause problems (explained below).
+            // This will report a warning
             richest.transfer(msg.value);
             richest = payable(msg.sender);
             mostSent = msg.value;
@@ -211,6 +213,7 @@ restrictions highly readable.
 
             _;
             if (msg.value > amount)
+                // This will report a warning
                 payable(msg.sender).transfer(msg.value - amount);
         }
 

docs/contracts/functions.rst

@@ -440,6 +440,7 @@ operations as long as there is enough gas passed on to it.
 
             // If someone sends Ether to that contract,
             // the transfer will fail, i.e. this returns false here.
+            // This will report a warning
             return testPayable.send(2 ether);
         }
 

docs/contracts/inheritance.rst

@@ -392,6 +392,7 @@ and the ``override`` keyword must be used in the overriding modifier:
 
     contract Base
     {
+        // This will report a warning
         modifier foo() virtual {_;}
     }
 
@@ -411,11 +412,13 @@ explicitly:
 
     contract Base1
     {
+        // This will report a warning
         modifier foo() virtual {_;}
     }
 
     contract Base2
     {
+        // This will report a warning
         modifier foo() virtual {_;}
     }
 

docs/control-structures.rst

@@ -698,6 +698,7 @@ and ``assert`` for internal error checking.
         function sendHalf(address payable addr) public payable returns (uint balance) {
             require(msg.value % 2 == 0, "Even value required.");
             uint balanceBeforeTransfer = address(this).balance;
+            // This will report a warning
             addr.transfer(msg.value / 2);
             // Since transfer throws an exception on failure and
             // cannot call back here, there should be no way for us to
@@ -775,6 +776,7 @@ together with ``revert`` and the equivalent ``require``:
             if (msg.sender != owner)
                 revert Unauthorized();
 
+            // This will report a warning
             payable(msg.sender).transfer(address(this).balance);
         }
     }

docs/examples/blind-auction.rst

@@ -124,6 +124,7 @@ to receive their Ether - contracts cannot activate themselves.
                 // msg.sender is not of type `address payable` and must be
                 // explicitly converted using `payable(msg.sender)` in order
                 // use the member function `send()`.
+                // This will report a warning
                 if (!payable(msg.sender).send(amount)) {
                     // No need to call throw here, just reset the amount owing
                     pendingReturns[msg.sender] = amount;
@@ -160,6 +161,7 @@ to receive their Ether - contracts cannot activate themselves.
             emit AuctionEnded(highestBidder, highestBid);
 
             // 3. Interaction
+            // This will report a warning
             beneficiary.transfer(highestBid);
         }
     }
@@ -310,6 +312,7 @@ invalid bids.
                 // the same deposit.
                 bidToCheck.blindedBid = bytes32(0);
             }
+            // This will report a warning
             payable(msg.sender).transfer(refund);
         }
 
@@ -323,6 +326,7 @@ invalid bids.
                 // conditions -> effects -> interaction).
                 pendingReturns[msg.sender] = 0;
 
+                // This will report a warning
                 payable(msg.sender).transfer(amount);
             }
         }
@@ -336,6 +340,7 @@ invalid bids.
             if (ended) revert AuctionEndAlreadyCalled();
             emit AuctionEnded(highestBidder, highestBid);
             ended = true;
+            // This will report a warning
             beneficiary.transfer(highestBid);
         }
 

docs/examples/micropayment.rst

@@ -185,6 +185,7 @@ The full contract
             // this recreates the message that was signed on the client
             bytes32 message = prefixed(keccak256(abi.encodePacked(msg.sender, amount, nonce, this)));
             require(recoverSigner(message, signature) == owner);
+            // This will report a warning
             payable(msg.sender).transfer(amount);
         }
 
@@ -195,6 +196,7 @@ The full contract
         {
             require(msg.sender == owner);
             freeze();
+            // This will report a warning
             payable(msg.sender).transfer(address(this).balance);
         }
 
@@ -406,8 +408,10 @@ The full contract
             require(msg.sender == recipient);
             require(isValidSignature(amount, signature));
 
+            // This will report a warning
             recipient.transfer(amount);
             freeze();
+            // This will report a warning
             sender.transfer(address(this).balance);
         }
 
@@ -430,6 +434,7 @@ The full contract
         {
             require(block.timestamp >= expiration);
             freeze();
+            // This will report a warning
             sender.transfer(address(this).balance);
         }
 

docs/examples/safe-remote.rst

@@ -97,6 +97,7 @@ you can use state machine-like constructs inside a contract.
             // reentrancy-safe, because it is the
             // last call in this function and we
             // already changed the state.
+            // This will report a warning.
             seller.transfer(address(this).balance);
         }
 
@@ -128,6 +129,7 @@ you can use state machine-like constructs inside a contract.
             // can call in again here.
             state = State.Release;
 
+            // This will report a warning
             buyer.transfer(value);
         }
 
@@ -144,6 +146,7 @@ you can use state machine-like constructs inside a contract.
             // can call in again here.
             state = State.Inactive;
 
+            // This will report a warning
             seller.transfer(3 * value);
         }
     }

docs/security-considerations.rst

@@ -65,6 +65,7 @@ To give an example, the following code contains a bug (it is just a snippet and
         mapping(address => uint) shares;
         /// Withdraw your share.
         function withdraw() public {
+        // This will report a warning
             if (payable(msg.sender).send(shares[msg.sender]))
                 shares[msg.sender] = 0;
         }
@@ -109,6 +110,7 @@ To avoid reentrancy, you can use the Checks-Effects-Interactions pattern as demo
         function withdraw() public {
             uint share = shares[msg.sender];
             shares[msg.sender] = 0;
+            // This will report a warning
             payable(msg.sender).transfer(share);
         }
     }
@@ -255,6 +257,7 @@ Let's say you have a wallet contract like this:
         function transferTo(address payable dest, uint amount) public {
             // THE BUG IS RIGHT HERE, you must use msg.sender instead of tx.origin
             require(tx.origin == owner);
+            // This will report a warning
             dest.transfer(amount);
         }
     }

docs/types/reference-types.rst

@@ -729,6 +729,7 @@ shown in the following example:
                 return false;
             uint amount = c.amount;
             c.amount = 0;
+            // This will report a warning
             c.beneficiary.transfer(amount);
             return true;
         }