poc of a simple implementation of python range bases loop in c++

forInRange.cc

// poc of a simple implementation of python range bases loop in c++

#include "iostream"
#include "vector"

template <typename T>
struct Range {
  private:
    std::vector<T> _vecRange = {  };

  public:
    Range(T fromRange, const T toRange) noexcept{
      if ( fromRange == toRange ) return;
      const int8_t inc = fromRange > toRange ? -1:1;
      for ( this->_vecRange.push_back(fromRange) ; fromRange != toRange ;
            this->_vecRange.push_back(fromRange += inc)
        );
    }

    typename std::vector<T>::iterator begin() noexcept {
      return this->_vecRange.begin();
    }
    typename std::vector<T>::iterator end() noexcept{
      return this->_vecRange.end();
    }

};

std::int32_t main(std::int32_t argc, char const *argv[]) {

  std::printf("[ 0, 7 ] ( uint8_t ) \n");
  for ( const auto& entry: Range<std::uint8_t>(0, 7) ) {
    std::printf("%u\n", entry);
  }

  std::printf("[ 0, -7] ( int8_t ) \n");
  for ( const auto& entry: Range<std::int8_t>(0, -7) ) {
    std::printf("%d\n", entry);
  }

  std::printf("[ -7, 0] ( int16_t ) \n");
  for ( const auto& entry: Range<std::int16_t>(-7, 0) ) {
    std::printf("%d\n", entry);
  }

  std::printf("[ 7, 0 ] ( uint16_t ) \n");
  for ( const auto& entry: Range<std::uint16_t>(7, 0) ) {
    std::printf("%u\n", entry);
  }

  std::printf("[ -7, 7 ] ( int16_t ) \n");
  for ( const auto& entry: Range<std::int16_t>(-7, 7) ) {
    std::printf("%d\n", entry);
  }

  std::printf("[ 7.f, -7.f] ( float ) \n");
  for ( const auto& entry: Range<float>(7.f, -7.f) ) {
    std::printf("%f\n", entry);
  }

  std::printf("[ -7, -7 ] ( int32_t ) \n");
  for ( const auto& entry: Range<std::int32_t>(-7, -7) ) {
    std::printf("%d\n", entry);
  }

  std::printf("[ -7.0, -17.0 ] ( double ) \n");
  for ( const auto& entry: Range<double>(-7.0, -17.0) ) {
    std::printf("%f\n", entry);
  }

  std::printf("[ -17, -7 ] ( int32_t ) \n");
  for ( const auto& entry: Range<std::int32_t>(-17, -7) ) {
    std::printf("%d\n", entry);
  }

  return 0;
}


/* Output

[ 0, 7 ] ( uint8_t ) 
0
1
2
3
4
5
6
7
[ 0, -7] ( int8_t ) 
0
-1
-2
-3
-4
-5
-6
-7
[ -7, 0] ( int16_t ) 
-7
-6
-5
-4
-3
-2
-1
0
[ 7, 0 ] ( uint16_t ) 
7
6
5
4
3
2
1
0
[ -7, 7 ] ( int16_t ) 
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
[ 7, -7] ( float ) 
7.000000
6.000000
5.000000
4.000000
3.000000
2.000000
1.000000
0.000000
-1.000000
-2.000000
-3.000000
-4.000000
-5.000000
-6.000000
-7.000000
[ -7, -7 ] ( int32_t ) 
[ -7.0, -17.0 ] ( double ) 
-7.000000
-8.000000
-9.000000
-10.000000
-11.000000
-12.000000
-13.000000
-14.000000
-15.000000
-16.000000
-17.000000
[ -17, -7 ] ( int32_t ) 
-17
-16
-15
-14
-13
-12
-11
-10
-9
-8
-7

*/