C++ linker presentation

cpplinker/07_linker_errors/undefined_ref/build.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+echo "=== This build SHOULD fail with 'undefined reference' ==="
+echo ""
+g++ -std=c++17 main.cpp -o app 2>&1 || true
+echo ""
+echo "The linker cannot find a definition for add(int, int)."
+echo "Fix: provide the .cpp that defines it, or link the correct library."

cpplinker/07_linker_errors/undefined_ref/main.cpp

@@ -0,0 +1,8 @@
+#include <iostream>
+
+int add(int, int);  // declared but never defined
+
+int main() {
+    std::cout << add(3, 4) << "\n";
+    return 0;
+}