lang/nttplambda.cpp

The following code example is taken from the book
C++20 - The Complete Guide by Nicolai M. Josuttis, Leanpub, 2021
The code is licensed under a Creative Commons Attribution 4.0 International License.

---

// raw code

#include <iostream>
#include <cmath>

template<std::invocable auto GetVat>
int addTax(int value)
{
  return static_cast<int>(std::round(value * (1 + GetVat())));
}

int main()
{
  auto getDefaultTax = [] {
    return 0.19;
  };

  std::cout << addTax<getDefaultTax>(100) << '\n';
  std::cout << addTax<getDefaultTax>(4199) << '\n';
  std::cout << addTax<getDefaultTax>(1950) << '\n';
}