3 files changed, 65 insertions, 0 deletions
diff --git a/src/chapter0/lesson13/standard.cpp b/src/chapter0/lesson13/standard.cpp
new file mode 100644
index 0000000..e27bc87
--- /dev/null
+++ b/src/chapter0/lesson13/standard.cpp
@@ -0,0 +1,43 @@
+// This program prints the C++ language standard your compiler is currently
+// using
+
+#include <iostream>
+
+const int numStandards = 7;
+
+const long stdCode[numStandards] = {199711L, 201103L, 201402L, 201703L,
+                                    202002L, 202302L, 202612L};
+const char *stdName[numStandards] = {"Pre-C++11", "C++11", "C++14", "C++17",
+                                     "C++20",     "C++23", "C++26"};
+
+long getCPPStandard() {
+#if defined(_MSVC_LANG)
+  return _MSVC_LANG;
+#elif defined(_MSC_VER)
+  return -1;
+#else
+  return __cplusplus;
+#endif
+}
+
+int main() {
+  long standard = getCPPStandard();
+
+  if (standard == -1) {
+    std::cout << "Error: Unable to determine your language standard.\n";
+    return 0;
+  }
+
+  for (int i = 0; i < numStandards; ++i) {
+    // If the reported version is one of the finalized standard
+    // codes then we know exactly what version the compiler is
+    // running
+    if (standard == stdCode[i]) {
+      std::cout << "Your compiler is using " << stdName[i]
+                << " (language standard code " << standard << "L)\n";
+      break;
+    }
+  }
+
+  return 0;
+}
diff --git a/src/chapter0/lesson7/helloworld.cpp b/src/chapter0/lesson7/helloworld.cpp
new file mode 100644
index 0000000..b0a6bd2
--- /dev/null
+++ b/src/chapter0/lesson7/helloworld.cpp
@@ -0,0 +1,7 @@
+#include <cstdlib>
+#include <iostream>
+
+int main() {
+	std::cout << "Hello, world!\n";
+	return(EXIT_SUCCESS);
+}
diff --git a/src/chapter1/lesson4/unused_variables.cpp b/src/chapter1/lesson4/unused_variables.cpp
new file mode 100644
index 0000000..52d724f
--- /dev/null
+++ b/src/chapter1/lesson4/unused_variables.cpp
@@ -0,0 +1,15 @@
+#include <iostream>
+
+int main()
+{
+	[[maybe_unused]] double pi { 3.14159 };  // Don't complain if pi is unused
+    [[maybe_unused]] double gravity { 9.8 }; // Don't complain if gravity is unused
+    [[maybe_unused]] double phi { 1.61803 }; // Don't complain if phi is unused
+
+    std::cout << pi << '\n';
+    std::cout << phi << '\n';
+
+    // The compiler will no longer warn about gravity not being used
+
+    return 0;
+}