ex13_42_StrVec.h

#ifndef CP5_STRVEC_H_
#define CP5_STRVEC_H_

#include <memory>
#include <string>
#include <initializer_list>

class StrVec {
public:
    StrVec() : elements(nullptr), first_free(nullptr), cap(nullptr) {}
    StrVec(const StrVec&);
    StrVec(std::initializer_list<std::string>);
    StrVec& operator=(const StrVec&);
    ~StrVec();

    void push_back(const std::string&);
    size_t size() const { return first_free - elements; }
    size_t capacity() const { return cap - elements; }
    std::string* begin() const { return elements; }
    std::string* end() const { return first_free; }

    std::string& at(size_t pos) { return *(elements + pos); }
    const std::string& at(size_t pos) const { return *(elements + pos); }

    void reserve(size_t new_cap);
    void resize(size_t count);
    void resize(size_t count, const std::string&);

private:
    std::pair<std::string*, std::string*> alloc_n_copy(const std::string*,
                                                       const std::string*);
    void free();
    void chk_n_alloc()
    {
        if (size() == capacity()) reallocate();
    }
    void reallocate();
    void alloc_n_move(size_t new_cap);
    void range_initialize(const std::string*, const std::string*);

private:
    std::string* elements;
    std::string* first_free;
    std::string* cap;
    std::allocator<std::string> alloc;
};

#endif