C++ range implementation

range.hpp

#include <iostream>
#include <type_traits>
#include <limits>
#include <stdexcept>

template <typename I>
class range_t {
    static_assert(std::is_integral<I>::value, "Integer type required");
    
    class offset {
    public:
        offset(I value): value(value) {}
        operator I&() { return value; }
        I operator *() const { return value; }
    private:
        I value;
    };

public:
    
    range_t(I last): range_t(0, last) {}
    explicit range_t(I last, bool inc): range_t(0, last, inc) {}
    explicit range_t(I start, I last): range_t(start, last, false) {}
    explicit range_t(I start, I last, bool inc): start(start),
        last(inc && inc && last < std::numeric_limits<I>::max() ? last + 1 : last) {
            if (last < start) {
                throw std::range_error("Start has to be less than or equal to last");
            }
        }
    const offset& begin() const { return start; }
    const offset& end() const { return last; }
    
private:
    offset start, last;
};