Fix Solidity warnings

docs/control-structures.rst

@@ -20,10 +20,10 @@ For example, suppose we want our contract to
 accept one kind of external calls with two integers, we would write
 something like::
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract Simple {
-        function taker(uint _a, uint _b) {
+        function taker(uint _a, uint _b) public pure {
             // do something with _a and _b.
         }
     }
@@ -36,10 +36,14 @@ The output parameters can be declared with the same syntax after the
 the sum and the product of the two given integers, then we would
 write::
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract Simple {
-        function arithmetics(uint _a, uint _b) returns (uint o_sum, uint o_product) {
+        function arithmetics(uint _a, uint _b)
+            public
+            pure
+            returns (uint o_sum, uint o_product)
+        {
             o_sum = _a + _b;
             o_product = _a * _b;
         }
@@ -95,11 +99,11 @@ Internal Function Calls
 Functions of the current contract can be called directly ("internally"), also recursively, as seen in
 this nonsensical example::
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract C {
-        function g(uint a) returns (uint ret) { return f(); }
-        function f() returns (uint ret) { return g(7) + f(); }
+        function g(uint a) public pure returns (uint ret) { return f(); }
+        function f() internal pure returns (uint ret) { return g(7) + f(); }
     }
 
 These function calls are translated into simple jumps inside the EVM. This has
@@ -125,13 +129,13 @@ the gas can be specified with special options ``.value()`` and ``.gas()``, respe
     pragma solidity ^0.4.0;
 
     contract InfoFeed {
-        function info() payable returns (uint ret) { return 42; }
+        function info() public payable returns (uint ret) { return 42; }
     }
 
     contract Consumer {
         InfoFeed feed;
-        function setFeed(address addr) { feed = InfoFeed(addr); }
-        function callFeed() { feed.info.value(10).gas(800)(); }
+        function setFeed(address addr) public { feed = InfoFeed(addr); }
+        function public callFeed() { feed.info.value(10).gas(800)(); }
     }
 
 The modifier ``payable`` has to be used for ``info``, because otherwise, the `.value()`
@@ -180,11 +184,11 @@ parameters from the function declaration, but can be in arbitrary order.
     pragma solidity ^0.4.0;
 
     contract C {
-        function f(uint key, uint value) {
+        function f(uint key, uint value) public {
             // ...
         }
 
-        function g() {
+        function g() public {
             // named arguments
             f({value: 2, key: 3});
         }
@@ -198,11 +202,11 @@ Those parameters will still be present on the stack, but they are inaccessible.
 
 ::
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract C {
         // omitted name for parameter
-        function func(uint k, uint) returns(uint) {
+        function func(uint k, uint) public pure returns(uint) {
             return k;
         }
     }
@@ -225,7 +229,7 @@ creation-dependencies are not possible.
 
     contract D {
         uint x;
-        function D(uint a) payable {
+        function D(uint a) public payable {
             x = a;
         }
     }
@@ -233,11 +237,11 @@ creation-dependencies are not possible.
     contract C {
         D d = new D(4); // will be executed as part of C's constructor
 
-        function createD(uint arg) {
+        function createD(uint arg) public {
             D newD = new D(arg);
         }
 
-        function createAndEndowD(uint arg, uint amount) payable {
+        function createAndEndowD(uint arg, uint amount) public payable {
             // Send ether along with the creation
             D newD = (new D).value(amount)(arg);
         }
@@ -270,16 +274,16 @@ Destructuring Assignments and Returning Multiple Values
 
 Solidity internally allows tuple types, i.e. a list of objects of potentially different types whose size is a constant at compile-time. Those tuples can be used to return multiple values at the same time and also assign them to multiple variables (or LValues in general) at the same time::
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract C {
         uint[] data;
 
-        function f() returns (uint, bool, uint) {
+        function f() public pure returns (uint, bool, uint) {
             return (7, true, 2);
         }
 
-        function g() {
+        function g() public {
             // Declares and assigns the variables. Specifying the type explicitly is not possible.
             var (x, b, y) = f();
             // Assigns to a pre-existing variable.
@@ -326,10 +330,10 @@ As a result, the following code is illegal and cause the compiler to throw an er
 
     // This will not compile
 
-    pragma solidity ^0.4.0;
+    pragma solidity ^0.4.16;
 
     contract ScopingErrors {
-        function scoping() {
+        function scoping() public {
             uint i = 0;
 
             while (i++ < 1) {
@@ -341,7 +345,7 @@ As a result, the following code is illegal and cause the compiler to throw an er
             }
         }
 
-        function minimalScoping() {
+        function minimalScoping() public {
             {
                 uint same2 = 0;
             }
@@ -351,7 +355,7 @@ As a result, the following code is illegal and cause the compiler to throw an er
             }
         }
 
-        function forLoopScoping() {
+        function forLoopScoping() public {
             for (uint same3 = 0; same3 < 1; same3++) {
             }
 
@@ -364,9 +368,9 @@ In addition to this, if a variable is declared, it will be initialized at the be
 As a result, the following code is legal, despite being poorly written::
 
     pragma solidity ^0.4.0;
-    
+
     contract C {
-        function foo() returns (uint) {
+        function foo() public pure returns (uint) {
             // baz is implicitly initialized as 0
             uint bar = 5;
             if (true) {
@@ -412,7 +416,7 @@ and how ``assert`` can be used for internal error checking::
     pragma solidity ^0.4.0;
 
     contract Sharer {
-        function sendHalf(address addr) payable returns (uint balance) {
+        function sendHalf(address addr) public payable returns (uint balance) {
             require(msg.value % 2 == 0); // Only allow even numbers
             uint balanceBeforeTransfer = this.balance;
             addr.transfer(msg.value / 2);