Documentation.

docs/070-breaking-changes.rst

@@ -18,3 +18,5 @@ This section gives detailed instructions on how to update prior code for every b
 * Change ``now`` to ``block.timestamp``.
 * Change types of right operand in shift operators to unsigned types. For example change ``x >> (256 - y)`` to
   ``x >> uint(256 - y)``.
+* Remove the ``public`` keyword from every constructor.
+* Remove the ``internal`` keyword from every constructor and add ``abstract`` to the contract (if not already present).

docs/abi-spec.rst

@@ -537,11 +537,11 @@ For example,
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
 
     contract Test {
-        constructor() public { b = hex"12345678901234567890123456789012"; }
+        constructor() { b = hex"12345678901234567890123456789012"; }
         event Event(uint indexed a, bytes32 b);
         event Event2(uint indexed a, bytes32 b);
         function foo(uint a) public { emit Event(a, b); }

docs/common-patterns.rst

@@ -28,7 +28,7 @@ you receive the funds of the person who is now the richest.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract WithdrawalContract {
         address public richest;
@@ -36,7 +36,7 @@ you receive the funds of the person who is now the richest.
 
         mapping (address => uint) pendingWithdrawals;
 
-        constructor() public payable {
+        constructor() payable {
             richest = msg.sender;
             mostSent = msg.value;
         }
@@ -62,13 +62,13 @@ This is as opposed to the more intuitive sending pattern:
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract SendContract {
         address payable public richest;
         uint public mostSent;
 
-        constructor() public payable {
+        constructor() payable {
             richest = msg.sender;
             mostSent = msg.value;
         }

docs/contracts/constant-state-variables.rst

@@ -18,7 +18,7 @@ Not all types for constants and immutables are implemented at this time. The onl
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >0.6.4 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract C {
         uint constant X = 32**22 + 8;
@@ -28,7 +28,7 @@ Not all types for constants and immutables are implemented at this time. The onl
         uint immutable maxBalance;
         address immutable owner = msg.sender;
 
-        constructor(uint _decimals, address _reference) public {
+        constructor(uint _decimals, address _reference) {
             decimals = _decimals;
             // Assignments to immutables can even access the environment.
             maxBalance = _reference.balance;

docs/contracts/creating-contracts.rst

@@ -48,7 +48,7 @@ This means that cyclic creation dependencies are impossible.
 
         // This is the constructor which registers the
         // creator and the assigned name.
-        constructor(bytes32 _name) public {
+        constructor(bytes32 _name) {
             // State variables are accessed via their name
             // and not via e.g. `this.owner`. Functions can
             // be accessed directly or through `this.f`,

docs/contracts/function-modifiers.rst

@@ -18,10 +18,10 @@ if they are marked ``virtual``. For details, please see
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract owned {
-        constructor() public { owner = msg.sender; }
+        constructor() { owner = msg.sender; }
         address payable owner;
 
         // This contract only defines a modifier but does not use
@@ -63,7 +63,7 @@ if they are marked ``virtual``. For details, please see
         mapping (address => bool) registeredAddresses;
         uint price;
 
-        constructor(uint initialPrice) public { price = initialPrice; }
+        constructor(uint initialPrice) { price = initialPrice; }
 
         // It is important to also provide the
         // `payable` keyword here, otherwise the function will

docs/contracts/inheritance.rst

@@ -39,11 +39,11 @@ Details are given in the following example.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
 
     contract Owned {
-        constructor() public { owner = msg.sender; }
+        constructor() { owner = msg.sender; }
         address payable owner;
     }
 
@@ -80,7 +80,7 @@ Details are given in the following example.
     // also a base class of `Destructible`, yet there is only a single
     // instance of `owned` (as for virtual inheritance in C++).
     contract Named is Owned, Destructible {
-        constructor(bytes32 name) public {
+        constructor(bytes32 name) {
             Config config = Config(0xD5f9D8D94886E70b06E474c3fB14Fd43E2f23970);
             NameReg(config.lookup(1)).register(name);
         }
@@ -106,8 +106,8 @@ Details are given in the following example.
 
 
     // If a constructor takes an argument, it needs to be
-    // provided in the header (or modifier-invocation-style at
-    // the constructor of the derived contract (see below)).
+    // provided in the header or modifier-invocation-style at
+    // the constructor of the derived contract (see below).
     contract PriceFeed is Owned, Destructible, Named("GoldFeed") {
         function updateInfo(uint newInfo) public {
             if (msg.sender == owner) info = newInfo;
@@ -127,10 +127,10 @@ destruction request. The way this is done is problematic, as
 seen in the following example::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract owned {
-        constructor() public { owner = msg.sender; }
+        constructor() { owner = msg.sender; }
         address payable owner;
     }
 
@@ -157,10 +157,10 @@ explicitly in the final override, but this function will bypass
 ``Base1.destroy``. The way around this is to use ``super``::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract owned {
-        constructor() public { owner = msg.sender; }
+        constructor() { owner = msg.sender; }
         address payable owner;
     }
 
@@ -392,33 +392,39 @@ and all functions that are reachable from there through function calls.
 It does not include the constructor code or internal functions that are
 only called from the constructor.
 
-Constructor functions can be either ``public`` or ``internal``. If there is no
+If there is no
 constructor, the contract will assume the default constructor, which is
-equivalent to ``constructor() public {}``. For example:
+equivalent to ``constructor() {}``. For example:
 
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
-    contract A {
+    abstract contract A {
         uint public a;
 
-        constructor(uint _a) internal {
+        constructor(uint _a) {
             a = _a;
         }
     }
 
     contract B is A(1) {
-        constructor() public {}
+        constructor() {}
     }
 
-A constructor set as ``internal`` causes the contract to be marked as :ref:`abstract <abstract-contract>`.
+You can use internal parameters in a constructor (for example storage pointers). In this case,
+the contract has to be marked :ref:`abstract <abstract-contract>`, because these parameters
+cannot be assigned valid values from outside but only through the constructors of derived contracts.
 
 .. warning ::
     Prior to version 0.4.22, constructors were defined as functions with the same name as the contract.
     This syntax was deprecated and is not allowed anymore in version 0.5.0.
 
+.. warning ::
+    Prior to version 0.7.0, you had to specify the visibility of constructors as either
+    ``internal`` or ``public``.
+
 
 .. index:: ! base;constructor
 
@@ -430,21 +436,21 @@ linearization rules explained below. If the base constructors have arguments,
 derived contracts need to specify all of them. This can be done in two ways::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract Base {
         uint x;
-        constructor(uint _x) public { x = _x; }
+        constructor(uint _x) { x = _x; }
     }
 
     // Either directly specify in the inheritance list...
     contract Derived1 is Base(7) {
-        constructor() public {}
+        constructor() {}
     }
 
     // or through a "modifier" of the derived constructor.
     contract Derived2 is Base {
-        constructor(uint _y) Base(_y * _y) public {}
+        constructor(uint _y) Base(_y * _y) {}
     }
 
 One way is directly in the inheritance list (``is Base(7)``).  The other is in
@@ -511,14 +517,14 @@ One area where inheritance linearization is especially important and perhaps not
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract Base1 {
-        constructor() public {}
+        constructor() {}
     }
 
     contract Base2 {
-        constructor() public {}
+        constructor() {}
     }
 
     // Constructors are executed in the following order:
@@ -526,7 +532,7 @@ One area where inheritance linearization is especially important and perhaps not
     //  2 - Base2
     //  3 - Derived1
     contract Derived1 is Base1, Base2 {
-        constructor() public Base1() Base2() {}
+        constructor() Base1() Base2() {}
     }
 
     // Constructors are executed in the following order:
@@ -534,7 +540,7 @@ One area where inheritance linearization is especially important and perhaps not
     //  2 - Base1
     //  3 - Derived2
     contract Derived2 is Base2, Base1 {
-        constructor() public Base2() Base1() {}
+        constructor() Base2() Base1() {}
     }
 
     // Constructors are still executed in the following order:
@@ -542,7 +548,7 @@ One area where inheritance linearization is especially important and perhaps not
     //  2 - Base1
     //  3 - Derived3
     contract Derived3 is Base2, Base1 {
-        constructor() public Base1() Base2() {}
+        constructor() Base1() Base2() {}
     }
 
 

docs/control-structures.rst

@@ -188,11 +188,11 @@ is compiled so recursive creation-dependencies are not possible.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.2 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract D {
         uint public x;
-        constructor(uint a) public payable {
+        constructor(uint a) payable {
             x = a;
         }
     }
@@ -244,11 +244,11 @@ which only need to be created if there is a dispute.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.2 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract D {
         uint public x;
-        constructor(uint a) public {
+        constructor(uint a) {
             x = a;
         }
     }

docs/examples/blind-auction.rst

@@ -25,7 +25,7 @@ to receive their money - contracts cannot activate themselves.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract SimpleAuction {
         // Parameters of the auction. Times are either
@@ -60,7 +60,7 @@ to receive their money - contracts cannot activate themselves.
         constructor(
             uint _biddingTime,
             address payable _beneficiary
-        ) public {
+        ) {
             beneficiary = _beneficiary;
             auctionEndTime = block.timestamp + _biddingTime;
         }
@@ -186,7 +186,7 @@ invalid bids.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract BlindAuction {
         struct Bid {
@@ -220,7 +220,7 @@ invalid bids.
             uint _biddingTime,
             uint _revealTime,
             address payable _beneficiary
-        ) public {
+        ) {
             beneficiary = _beneficiary;
             biddingEnd = block.timestamp + _biddingTime;
             revealEnd = biddingEnd + _revealTime;

docs/examples/micropayment.rst

@@ -143,14 +143,14 @@ The full contract
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.24 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract ReceiverPays {
         address owner = msg.sender;
 
         mapping(uint256 => bool) usedNonces;
 
-        constructor() public payable {}
+        constructor() payable {}
 
         function claimPayment(uint256 amount, uint256 nonce, bytes memory signature) public {
             require(!usedNonces[nonce]);
@@ -340,7 +340,7 @@ The full contract
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract SimplePaymentChannel {
         address payable public sender;      // The account sending payments.
@@ -348,7 +348,6 @@ The full contract
         uint256 public expiration;  // Timeout in case the recipient never closes.
 
         constructor (address payable _recipient, uint256 duration)
-            public
             payable
         {
             sender = msg.sender;

docs/examples/safe-remote.rst

@@ -26,7 +26,7 @@ you can use state machine-like constructs inside a contract.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract Purchase {
         uint public value;
@@ -74,7 +74,7 @@ you can use state machine-like constructs inside a contract.
         // Ensure that `msg.value` is an even number.
         // Division will truncate if it is an odd number.
         // Check via multiplication that it wasn't an odd number.
-        constructor() public payable {
+        constructor() payable {
             seller = msg.sender;
             value = msg.value / 2;
             require((2 * value) == msg.value, "Value has to be even.");

docs/examples/voting.rst

@@ -33,7 +33,7 @@ of votes.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     /// @title Voting with delegation.
     contract Ballot {
@@ -63,7 +63,7 @@ of votes.
         Proposal[] public proposals;
 
         /// Create a new ballot to choose one of `proposalNames`.
-        constructor(bytes32[] memory proposalNames) public {
+        constructor(bytes32[] memory proposalNames) {
             chairperson = msg.sender;
             voters[chairperson].weight = 1;
 

docs/introduction-to-smart-contracts.rst

@@ -83,7 +83,7 @@ registering with a username and password, all you need is an Ethereum keypair.
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.5.99 <0.8.0;
 
     contract Coin {
         // The keyword "public" makes variables
@@ -97,7 +97,7 @@ registering with a username and password, all you need is an Ethereum keypair.
 
         // Constructor code is only run when the contract
         // is created
-        constructor() public {
+        constructor() {
             minter = msg.sender;
         }
 
@@ -186,7 +186,7 @@ and any user interface calls the automatically generated ``balances`` function f
 
 .. index:: coin
 
-The :ref:`constructor<constructor>` is a special function run during the creation of the contract and
+The :ref:`constructor<constructor>` is a special function that is executed during the creation of the contract and
 cannot be called afterwards. In this case, it permanently stores the address of the person creating the
 contract. The ``msg`` variable (together with ``tx`` and ``block``) is a
 :ref:`special global variable <special-variables-functions>` that

docs/security-considerations.rst

@@ -201,13 +201,13 @@ Never use tx.origin for authorization. Let's say you have a wallet contract like
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.5.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     // THIS CONTRACT CONTAINS A BUG - DO NOT USE
     contract TxUserWallet {
         address owner;
 
-        constructor() public {
+        constructor() {
             owner = msg.sender;
         }
 
@@ -222,7 +222,7 @@ Now someone tricks you into sending Ether to the address of this attack wallet:
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     interface TxUserWallet {
         function transferTo(address payable dest, uint amount) external;
@@ -231,7 +231,7 @@ Now someone tricks you into sending Ether to the address of this attack wallet:
     contract TxAttackWallet {
         address payable owner;
 
-        constructor() public {
+        constructor() {
             owner = msg.sender;
         }
 

docs/style-guide.rst

@@ -300,10 +300,10 @@ Within a grouping, place the ``view`` and ``pure`` functions last.
 Yes::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract A {
-        constructor() public {
+        constructor() {
             // ...
         }
 
@@ -337,7 +337,7 @@ Yes::
 No::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract A {
 
@@ -357,7 +357,7 @@ No::
         // Public functions
         // ...
 
-        constructor() public {
+        constructor() {
             // ...
         }
 
@@ -758,19 +758,19 @@ manner as modifiers if the function declaration is long or hard to read.
 Yes::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     // Base contracts just to make this compile
     contract B {
-        constructor(uint) public {
+        constructor(uint) {
         }
     }
     contract C {
-        constructor(uint, uint) public {
+        constructor(uint, uint) {
         }
     }
     contract D {
-        constructor(uint) public {
+        constructor(uint) {
         }
     }
 
@@ -781,7 +781,6 @@ Yes::
             B(param1)
             C(param2, param3)
             D(param4)
-            public
         {
             // do something with param5
             x = param5;
@@ -791,24 +790,24 @@ Yes::
 No::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
 
     // Base contracts just to make this compile
     contract B {
-        constructor(uint) public {
+        constructor(uint) {
         }
     }
 
 
     contract C {
-        constructor(uint, uint) public {
+        constructor(uint, uint) {
         }
     }
 
 
     contract D {
-        constructor(uint) public {
+        constructor(uint) {
         }
     }
 
@@ -819,8 +818,7 @@ No::
         constructor(uint param1, uint param2, uint param3, uint param4, uint param5)
         B(param1)
         C(param2, param3)
-        D(param4)
-        public {
+        D(param4) {
             x = param5;
         }
     }
@@ -832,8 +830,7 @@ No::
         constructor(uint param1, uint param2, uint param3, uint param4, uint param5)
             B(param1)
             C(param2, param3)
-            D(param4)
-            public {
+            D(param4) {
                 x = param5;
             }
     }
@@ -1015,14 +1012,14 @@ As shown in the example below, if the contract name is ``Congress`` and the libr
 Yes::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
 
     // Owned.sol
     contract Owned {
         address public owner;
 
-        constructor() public {
+        constructor() {
             owner = msg.sender;
         }
 
@@ -1051,14 +1048,14 @@ and in ``Congress.sol``::
 No::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.4.22 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
 
     // owned.sol
     contract owned {
         address public owner;
 
-        constructor() public {
+        constructor() {
             owner = msg.sender;
         }
 
@@ -1096,7 +1093,7 @@ Events should be named using the CapWords style. Examples: ``Deposit``, ``Transf
 Function Names
 ==============
 
-Functions other than constructors should use mixedCase. Examples: ``getBalance``, ``transfer``, ``verifyOwner``, ``addMember``, ``changeOwner``.
+Functions should use mixedCase. Examples: ``getBalance``, ``transfer``, ``verifyOwner``, ``addMember``, ``changeOwner``.
 
 
 Function Argument Names

docs/types/reference-types.rst

@@ -417,13 +417,13 @@ Array slices are useful to ABI-decode secondary data passed in function paramete
 ::
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     contract Proxy {
         /// @dev Address of the client contract managed by proxy i.e., this contract
         address client;
 
-        constructor(address _client) public {
+        constructor(address _client) {
             client = _client;
         }
 

docs/using-the-compiler.rst

@@ -721,7 +721,7 @@ The command above applies all changes as shown below. Please review them careful
 .. code-block:: solidity
 
     // SPDX-License-Identifier: GPL-3.0
-    pragma solidity >=0.6.0 <0.8.0;
+    pragma solidity >0.6.99 <0.8.0;
 
     abstract contract Updateable {
         function run() public view virtual returns (bool);
@@ -734,7 +734,7 @@ The command above applies all changes as shown below. Please review them careful
     }
 
     contract Source is Updateable, Upgradable {
-        constructor() public {}
+        constructor() {}
 
         function run()
             public