#include <iostream>
#include <string>
/*
* generic_swap
* ------------
* A fully generic C++ swap function implemented using templates.
*
* Parameters:
* a, b - references to the two objects to swap
*
* This function uses std::swap internally, which is the idiomatic
* and type‑safe way to swap objects in C++. It works for:
* - built‑in types (int, double, etc.)
* - std::string
* - structs/classes
* - containers
* - user‑defined types with a valid swap operation
*/
template <typename T>
void generic_swap(T& a, T& b) {
std::swap(a, b);
}
/*
* Print arrays of integers
*/
void print_int_array(const int* arr, int n) {
for (int i = 0; i < n; i++)
std::cout << arr[i] << " ";
std::cout << "\n";
}
int main() {
std::cout << "=== TEST 1: Swap integers ===\n";
int x = 10, y = 20;
std::cout << "Before: x=" << x << ", y=" << y << "\n";
generic_swap(x, y);
std::cout << "After: x=" << x << ", y=" << y << "\n\n";
std::cout << "=== TEST 2: Swap doubles ===\n";
double a = 3.14, b = 2.71;
std::cout << "Before: a=" << a << ", b=" << b << "\n";
generic_swap(a, b);
std::cout << "After: a=" << a << ", b=" << b << "\n\n";
std::cout << "=== TEST 3: Swap structs ===\n";
struct Point { int x, y; };
Point p1{1, 2}, p2{9, 8};
std::cout << "Before: p1=(" << p1.x << "," << p1.y
<< "), p2=(" << p2.x << "," << p2.y << ")\n";
generic_swap(p1, p2);
std::cout << "After: p1=(" << p1.x << "," << p1.y
<< "), p2=(" << p2.x << "," << p2.y << ")\n\n";
std::cout << "=== TEST 4: Swap array elements ===\n";
int arr[] = {1, 2, 3, 4, 5};
std::cout << "Before: ";
print_int_array(arr, 5);
generic_swap(arr[1], arr[3]);
std::cout << "After: ";
print_int_array(arr, 5);
std::cout << "\n";
std::cout << "=== TEST 5: Swap strings ===\n";
std::string str1 = "Hello";
std::string str2 = "World";
std::cout << "Before: str1=\"" << str1 << "\", str2=\"" << str2 << "\"\n";
generic_swap(str1, str2);
std::cout << "After: str1=\"" << str1 << "\", str2=\"" << str2 << "\"\n\n";
}
/*
run:
=== TEST 1: Swap integers ===
Before: x=10, y=20
After: x=20, y=10
=== TEST 2: Swap doubles ===
Before: a=3.14, b=2.71
After: a=2.71, b=3.14
=== TEST 3: Swap structs ===
Before: p1=(1,2), p2=(9,8)
After: p1=(9,8), p2=(1,2)
=== TEST 4: Swap array elements ===
Before: 1 2 3 4 5
After: 1 4 3 2 5
=== TEST 5: Swap strings ===
Before: str1="Hello", str2="World"
After: str1="World", str2="Hello"
*/
