Merge branch 'master' into 'master'

code style changes

See merge request jg943598/rpn_calculator!15

src/main.cpp

@@ -9,7 +9,7 @@
 /*
  * Adds two integers
  */
-int add(int a, int b) {
+int add(const int a, const int b) {
   int res;
   bool overflow = __builtin_sadd_overflow(a, b, &res);
   if (overflow) {
@@ -21,7 +21,7 @@ int add(int a, int b) {
 /*
  * Multiplies two integers
  */
-int multiply(int a, int b) {
+int multiply(const int a, const int b) {
   int res;
   bool overflow = __builtin_smul_overflow(a, b, &res);
   if (overflow) {
@@ -33,7 +33,7 @@ int multiply(int a, int b) {
 /*
  * Subtracts integer b from integer a
  */
-int subtract(int a, int b) {
+int subtract(const int a, const int b) {
   int res;
   bool overflow = __builtin_ssub_overflow(b, a, &res);
   if (overflow) {
@@ -46,7 +46,7 @@ int subtract(int a, int b) {
  * Divides integer b from integer a, throwing an exception when b is zero.
  * Throws an std::invalid_argument exceptions if invalid parameters are provided.
  */
-int divide(int a, int b) {
+int divide(const int a, const int b) {
   if (b == 0) {
     throw std::invalid_argument("Malformed input. Division by zero.");
   }
@@ -55,15 +55,13 @@ int divide(int a, int b) {
 
 using binary_operator = decltype(&add);
 
-std::unordered_map<char, binary_operator> map {
-  {'+', add},
-  {'-', subtract},
-  {'*', multiply},
-  {'/', divide}
-};
-
 int evaluate(const std::string &s) {
-  int a, b;
+  static const std::unordered_map<char, binary_operator> map {
+    {'+', add},
+    {'-', subtract},
+    {'*', multiply},
+    {'/', divide}
+  };
   decltype(map)::iterator iter;
   std::stack<int> stack;
 
@@ -73,9 +71,9 @@ int evaluate(const std::string &s) {
     } else if (stack.size() >= 2 ) {
         iter = map.find(c);
         if (iter != map.end()) {
-          a = stack.top();
+          const auto a = stack.top();
           stack.pop();
-          b = stack.top();
+          const auto b = stack.top();
           stack.pop();
           stack.push(iter->second(b, a));
         } else {
@@ -112,5 +110,4 @@ int main() {
   if (result != INT_MAX) {
     std::cout << "Result is: " << result << '\n';
   }
-
 }