literal.cpp

//
// Created by light on 19-12-25.
//

#include <chrono>

#include <bitset>
#include <complex>
#include <iostream>
#include <string>
#include <thread>

using namespace std::literals::chrono_literals;
using namespace std::literals::string_literals;
using namespace std::literals::complex_literals;

struct length {
  double value;
  enum unit {
    metre,
    kilometre,
    millimetre,
    centimetre,
    inch,
    foot,
    yard,
    mile,
  };
  static constexpr double factors[] = {1.0,    1000.0, 1e-3,   1e-2,
                                       0.0254, 0.3048, 0.9144, 1609.344};

  explicit length(double v, unit u = metre) { value = v * factors[u]; }
};

length operator+(length lhs, length rhs) {
  return length(lhs.value + rhs.value);
}

length operator"" _m(long double v) { return length(v, length::metre); }

length operator"" _cm(long double v) { return length(v, length::centimetre); }

//  可能有其他运算符
int main() {

  std::cout << "i * i = " << 1i * 1i << std::endl;
  std::cout << "Waiting for 500ms" << std::endl;
  std::this_thread::sleep_for(500ms);
  std::cout << "Hello world"s.substr(0, 5) << std::endl;

  length l1 = length(1.0, length::metre);
  length l2 = length(1.0, length::centimetre);
  std::cout << l2.value << std::endl;
  std::cout << (l1 + l2).value << std::endl;

  // 1.0_m + 10.0_cm
  std::cout << (1.0_m + 1.0_cm).value << std::endl;

  // 二进制字面量
  unsigned mask = 0b1101;
  // 以十进制打印
  std::cout << mask << std::endl;

  // 打印二进制字面量
  std::cout << std::bitset<4>(mask) << std::endl;

  // 数字分隔符
  unsigned mk = 0b111'000'000;
  double pi = 3.141'5926;
  return 0;
}