Fix C++ code smells

* Move "using namespace std;" from header to module file (to no longer pollute the global namespace).
* Fix inconsistency of having namespace prefix in test code.
* Add include guard to GildedRose.h.
* Avoid std::endl.
* Have consistent white-space.

cpp/src/GildedRose.cc

@@ -1,5 +1,7 @@
 #include "GildedRose.h"
 
+using namespace std;
+
 GildedRose::GildedRose(vector<Item> & items) : items(items)
 {}
     

cpp/src/GildedRose.h

@@ -1,24 +1,23 @@
+#pragma once
+
 #include <string>
 #include <vector>
 
-using namespace std;
-
 class Item
 {
 public:
-    string name;
+    std::string name;
     int sellIn;
     int quality;
-    Item(string name, int sellIn, int quality) : name(name), sellIn(sellIn), quality(quality) 
+    Item(std::string name, int sellIn, int quality) : name(name), sellIn(sellIn), quality(quality) 
     {}
 };
 
 class GildedRose
 {
 public:
-    vector<Item> & items;
+    std::vector<Item> & items;
-    GildedRose(vector<Item> & items);
+    GildedRose(std::vector<Item> & items);
     
     void updateQuality();
 };
-

cpp/test/cpp_catch2_approvaltest/GildedRoseCatch2ApprovalTests.cc

@@ -12,12 +12,12 @@ std::ostream& operator<<(std::ostream& os, const Item& obj)
 
 TEST_CASE("GildedRoseApprovalTests", "VerifyCombinations")
 {
-    std::vector<string> names { "Foo" };
+    std::vector<std::string> names { "Foo" };
     std::vector<int> sellIns { 1 };
     std::vector<int> qualities { 1 };
 
-    auto f = [](string name, int sellIn, int quality) {
+    auto f = [](std::string name, int sellIn, int quality) {
-        vector<Item> items = {Item(name, sellIn, quality)};
+        std::vector<Item> items = {Item(name, sellIn, quality)};
         GildedRose app(items);
         app.updateQuality();
         return items[0];

cpp/test/cpp_catch2_unittest/GildedRoseCatch2UnitTests.cc

@@ -3,7 +3,7 @@
 
 TEST_CASE("GildedRoseUnitTest", "Foo")
 {
-    vector<Item> items;
+    std::vector<Item> items;
     items.push_back(Item("Foo", 0, 0));
     GildedRose app(items);
     app.updateQuality();

cpp/test/cpp_googletest_approvaltest/GildedRoseGoogletestApprovalTests.cc

@@ -12,12 +12,12 @@ std::ostream& operator<<(std::ostream& os, const Item& obj)
 
 TEST(GildedRoseApprovalTests, VerifyCombinations) {
 
-    std::vector<string> names { "Foo" };
+    std::vector<std::string> names { "Foo" };
     std::vector<int> sellIns { 1 };
     std::vector<int> qualities { 1 };
 
-    auto f = [](string name, int sellIn, int quality) {
+    auto f = [](std::string name, int sellIn, int quality) {
-        vector<Item> items = {Item(name, sellIn, quality)};
+        std::vector<Item> items = {Item(name, sellIn, quality)};
         GildedRose app(items);
         app.updateQuality();
         return items[0];

cpp/test/cpp_googletest_unittest/GildedRoseGoogletestUnitTests.cc

@@ -2,7 +2,7 @@
 #include "GildedRose.h"
 
 TEST(GildedRoseTest, Foo) {
-    vector<Item> items;
+    std::vector<Item> items;
     items.push_back(Item("Foo", 0, 0));
     GildedRose app(items);
     app.updateQuality();

cpp/test/cpp_texttest/GildedRoseTextTests.cc

@@ -3,12 +3,12 @@
 
 void print_item(Item& item)
 {
-    std::cout << item.name << ", " <<  item.sellIn << ", " << item.quality << std::endl;
+    std::cout << item.name << ", " <<  item.sellIn << ", " << item.quality << '\n';
 }
 
 int main()
 {
-    vector<Item> items;
+    std::vector<Item> items;
 
     items.push_back({"+5 Dexterity Vest", 10, 20});
     items.push_back({"Aged Brie", 2, 0});
@@ -22,22 +22,20 @@ int main()
     // this Conjured item doesn't yet work properly
     items.push_back({"Conjured Mana Cake", 3, 6});
 
-	std::cout << "OMGHAI!" << std::endl;
+    std::cout << "OMGHAI!" << '\n';
 
     GildedRose app(items);
 
     for (int day = 0; day <= 30; day++)
     {
-		std::cout << "-------- day " << day << " --------" << std::endl;
+        std::cout << "-------- day " << day << " --------" << '\n';
-		std::cout << "name, sellIn, quality" << std::endl;
+        std::cout << "name, sellIn, quality" << '\n';
         for (auto& item : items)
         {
             print_item(item);
         }
-		std::cout << std::endl;
+        std::cout << '\n';
         app.updateQuality();
     }
     return 0;
 }
-
-