C++ examples for template:template class
Using the templates for overloaded comparison operators for Pool objects
#include <iostream> #include <string> #include <vector> #include <utility> #include <iostream> class Pool/* w w w . j a v a2 s.c o m*/ { private: double length {1.0}; double width {1.0}; double height {1.0}; public: // Constructors Pool(double lv, double wv, double hv) : length {lv}, width {wv}, height {hv} {} Pool() {} // No-arg constructor Pool(const Pool& pool) // Copy constructor : length {pool.length}, width {pool.width}, height {pool.height} {} double volume() const // Function to calculate the volume { return length*width*height; } // Accessors double getLength() const { return length; } double getWidth() const { return width; } double getHeight() const { return height; } bool operator<(const Pool& aPool) const; // Less-than operator bool operator<(double aValue) const; // Compare Pool volume < double value // Equality operator bool operator==(const Pool& aPool) const { return volume() == aPool.volume(); } }; // Less-than comparison for Pool objects inline bool Pool::operator<(const Pool& aPool) const { return volume() < aPool.volume(); } // Compare the volume of a Pool object with a constant inline bool Pool::operator<(double aValue) const { return volume() < aValue; } // Function comparing a constant with volume of a Pool object inline bool operator<(double aValue, const Pool& aPool) { return aValue < aPool.volume(); } using namespace std::rel_ops; void show(const Pool& pool1, const std::string relationship, const Pool& pool2) { std::cout << "Pool " << pool1.getLength() << "x" << pool1.getWidth() << "x" << pool1.getHeight() << relationship << "Pool " << pool2.getLength() << "x" << pool2.getWidth() << "x" << pool2.getHeight() << std::endl; } int main() { std::vector<Pool> pools {Pool {2.0, 2.0, 3.0}, Pool {1.0, 3.0, 2.0}, Pool {1.0, 2.0, 1.0}, Pool {2.0, 3.0, 3.0}}; Pool thePool {3.0, 1.0, 3.0}; for (auto& pool : pools) if (thePool > pool) show(thePool, " is greater than ", pool); std::cout << std::endl; for (auto& pool : pools) if (thePool != pool) show(thePool, " is not equal to ", pool); std::cout << std::endl; for (int i {}; i < pools.size() - 1; ++i) for (int j {i + 1}; j < pools.size(); ++j) { if (pools[i] <= pools[j]) show(pools[i], " less than or equal to ", pools[j]); } }