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Generic Programming Templates in C++

- Examples

Explore how to implement and use constexpr functions in C++11 and C++14 to enable compile-time evaluation. Learn through examples how these functions improve code efficiency and how template features support automatic return types and constexpr usage.

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Example 1: constexpr using C++ 11

C++
// constExpression.cpp
#include <iostream>
constexpr int square(int x) { return x * x; }
constexpr int squareToSquare(int x){ return square(square(x));}
int main() {
  std::cout << std::endl;
  static_assert(square(10) == 100, "you calculated it wrong");
  static_assert(squareToSquare(10) == 10000 , "you calculated it wrong");
  std::cout<< "square(10)= " << square(10) << std::endl;
  std::cout<< "squareToSquare(10)= " << squareToSquare(10) << std::endl;
  constexpr int constExpr= square(10);
  int arrayClassic[100];
  int arrayNewWithConstExpression[constExpr];
  int arrayNewWithConstExpressioFunction[square(10)];
  std::cout << std::endl;
}

Explanation

  • In the example above, we have implemented two constexpr functions: constexpr int square(int x) and constexpr int squareToSquare(int x). As you can see, both the functions follow ...