I felt that I ported the Python code to C ++ 98.

Even if you can write it concisely in Python, you need to write a huge amount of template code in C ++ 98. For reference, I arranged the C ++ and Python code side by side.

In a nutshell, "Syntactic sugar and dynamic typing are great."

(Because it is about to be written, there may be more items in the future)

Part 1 Static / Dynamic Typing

Point get_distance(const Point& point1, const Point& point2) {
  return sqrt( pow(point1.x - point2.x, 2) + pow(point1.y - point2.y, 2);
def get_distance(point1, point2):
  pt1_x, pt1_y = point1
  pt2_x, pt2_y = point2
  return math.sqrt((pt1_x - pt2_x) ** 2, (pt1_y - pt2_y) ** 2)

C ++: In addition to types, modifiers such as const, *, &, and templates are annoying. (I / O is specified, and syntax check at compile time is helpful, but ...) Python: Dynamically typed, no type definition required. The type has a value, not a variable.

Part 2 List and dictionary

vector<double> calculate(const vector<Line>& lines) {
  vector<double> result;
  vector<Line>::const_iterator ite = lines.begin();
  while( ite != lines.end() ) {
    double value =Do something(*ite);
  return result;
def calculate(lines):
  result = [] // []In list format, {}Then the dictionary.
  for line in lines:
    value =Do something(line)
  return result

C ++: In C ++ 98, there is no syntactic sugar (C ++ 11 has syntactic sugar).

python: Object creation, element access, syntax sugar in loops. The above case can be described more concisely using list comprehensions.

def calculate(lines):
  result = [Do something(line) for line in lines]
  return result

Part 3 tuple

void foo() {
  Point pt1(0,1);
  Point pt2(0,5);
  Line line(pt1, pt2);

  double score;
  double distance;
  calculate(line, &score, &distance); 

void calculate(const Line& line, double* out_score, double* out_distance) {
  *out_distance = get_distance(line.point1, line.point2);
  *out_score = get_score(line);

double get_distance(const Point& pt1, const Point& pt2) {...}

def foo():
  pt1 = (0,1)
  pt2 = (0,5)
  line = (pt1, pt2)
  distance, score = caclculate(line)

def calculate(line):
  distance = get_distance(*line)
  score = get_score(line)
  return distance, score

def get_distance(pt1, pt2):

C ++: If you want to group values, you need to use a generic pair or define a struct / class like Point or Line. This is also a trade-off with syntax checking.

Python: Tuples come in handy when you want to pass a small pair as an argument. Overuse will reduce readability.

Part 4 Lambda expression

void foo(const Line& line, double x) {
  double y1 = func(line, x);
  double y2 = func(line, x+1);

//Find the y coordinate corresponding to x on the straight line.
// ※:y=1 or x=Do not consider lines such as 0.
double func(const Line& line, double x) {
   //Get tilt
   double slope = get_slope(line.point1, line.point2);
   double const_value = get_const_value(line.point1, slope);
   double y = x * slope + c;
   return y;

def foo(line, x):
  func = get_func(line)
  y1 = func(x)
  y2 = func(x + 1)

def get_func(line):
  slope = get_slope(*line)
  const_value = get_const_value(line[0], slope)
  return (lamda x: x * slope + c)

Lambda expressions are provided in python, so you can easily write small things. In C ++, writing a class improves reusability, but the threshold for writing is high.

Part 5 Function call

You can easily expand tuples and lists into individual arguments, or create named arguments.

Example: Reduce C ++ function overloads.

doule get_distance(const Point& pt1, const Point pt2) {
   return //Calculation result

double get_distance(const Line& line) {
  return get_distance(line.point1, line.point2);
def get_distance(point1, point2):
  return ...

def foo(line):
  get_distance(*line) //If line is a tuple or sequence, point1 automatically,Expand to point2.

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