Adding structured bindings

Author: harris2001

C++17/fold_expressions.cpp

@@ -1,8 +1,8 @@
-//#include <print> // Needs to be included if we are using C++23 print function
 #include <iostream>
 #include <vector>
 #include <set>
 #include <string>
+//#include <print> // Needs to be included if we are using C++23 print function
 
 //size_t... I is a std::integer_sequence whose values are specified by a non-type template
 template<typename TupleT, size_t... IdxT>

C++17/structured_bindings.cpp

@@ -0,0 +1,45 @@
+/*
+ * 3. STRUCTURED BINDINGS:
+ *
+ * Structured bindings allow us to unpack tuples, pairs, arrays and other packed structures
+ *      directly into variables to improve code readability.
+ * They essentially perform tuple decomposition and let us bind the contained values into 
+ *      local variables. 
+ */
+#include <iostream>
+#include <tuple>
+#include <cassert>
+
+struct Point
+{
+	int x;
+	int y;
+	int z;
+};
+
+std::tuple<int, double, std::string> getValues()
+{
+	return {1, 3.14, "something"};
+}
+
+int main()
+{
+	std::cout << "===== Test: Structured Bindings with tuple =====\n";
+	// This is the strucuted binding part where the lhs is a list of variable names
+	// and the rhs is the container (in this case a tuple)
+	auto [num, pi, str] = getValues(); 
+
+	assert(num == 1);
+	assert(pi == 3.14);
+	assert(str == "something");
+
+
+	Point p{1, 2, 3};
+	// here we decompose a Point object into separate variables
+	auto [a, b, c] = p;	
+	assert(a == 1);
+	assert(b == 2);
+	assert(c == 3);
+
+	return 0;
+}

CMakeLists.txt

@@ -3,8 +3,10 @@ project(CppExamples LANGUAGES CXX)
 
 enable_testing()
 
-set(SUBDIRS C++11)
-set(SUBDIRS C++17)
+set(SUBDIRS 
+	C++11
+	C++17
+   )
 
 foreach(SUBDIR ${SUBDIRS})
     add_subdirectory(${SUBDIR})