constexpr basic_string& operator+=(const basic_string& str);
template<class T>
constexpr basic_string& operator+=(const T& t);
constexpr basic_string& operator+=(const charT* s);
constexpr basic_string& operator+=(charT c);
constexpr basic_string& operator+=(initializer_list<charT> il);
constexpr basic_string& append(const basic_string& str);
constexpr basic_string& append(const basic_string& str, size_type pos, size_type n = npos);
template<class T>
constexpr basic_string& append(const T& t);
template<class T>
constexpr basic_string& append(const T& t, size_type pos, size_type n = npos);
constexpr basic_string& append(const charT* s, size_type n);
constexpr basic_string& append(const charT* s);
constexpr basic_string& append(size_type n, charT c);
template<class InputIterator>
constexpr basic_string& append(InputIterator first, InputIterator last);
template<container-compatible-range<charT> R>
constexpr basic_string& append_range(R&& rg);
constexpr basic_string& append(initializer_list<charT> il);
constexpr void push_back(charT c);
constexpr basic_string& assign(const basic_string& str);
constexpr basic_string& assign(basic_string&& str)
noexcept(allocator_traits<Allocator>::propagate_on_container_move_assignment::value ||
allocator_traits<Allocator>::is_always_equal::value);
constexpr basic_string& assign(const basic_string& str, size_type pos, size_type n = npos);
template<class T>
constexpr basic_string& assign(const T& t);
template<class T>
constexpr basic_string& assign(const T& t, size_type pos, size_type n = npos);
constexpr basic_string& assign(const charT* s, size_type n);
constexpr basic_string& assign(const charT* s);
constexpr basic_string& assign(initializer_list<charT> il);
constexpr basic_string& assign(size_type n, charT c);
template<class InputIterator>
constexpr basic_string& assign(InputIterator first, InputIterator last);
template<container-compatible-range<charT> R>
constexpr basic_string& assign_range(R&& rg);
constexpr basic_string& insert(size_type pos, const basic_string& str);
constexpr basic_string& insert(size_type pos1, const basic_string& str,
size_type pos2, size_type n = npos);
template<class T>
constexpr basic_string& insert(size_type pos, const T& t);
template<class T>
constexpr basic_string& insert(size_type pos1, const T& t,
size_type pos2, size_type n = npos);
constexpr basic_string& insert(size_type pos, const charT* s, size_type n);
constexpr basic_string& insert(size_type pos, const charT* s);
constexpr basic_string& insert(size_type pos, size_type n, charT c);
constexpr iterator insert(const_iterator p, charT c);
constexpr iterator insert(const_iterator p, size_type n, charT c);
template<class InputIterator>
constexpr iterator insert(const_iterator p, InputIterator first, InputIterator last);
template<container-compatible-range<charT> R>
constexpr iterator insert_range(const_iterator p, R&& rg);
constexpr iterator insert(const_iterator p, initializer_list<charT> il);
constexpr basic_string& erase(size_type pos = 0, size_type n = npos);
constexpr iterator erase(const_iterator p);
constexpr iterator erase(const_iterator first, const_iterator last);
constexpr void pop_back();
constexpr basic_string& replace(size_type pos1, size_type n1, const basic_string& str);
constexpr basic_string& replace(size_type pos1, size_type n1, const basic_string& str,
size_type pos2, size_type n2 = npos);
template<class T>
constexpr basic_string& replace(size_type pos1, size_type n1, const T& t);
template<class T>
constexpr basic_string& replace(size_type pos1, size_type n1, const T& t,
size_type pos2, size_type n2 = npos);
constexpr basic_string& replace(size_type pos1, size_type n1, const charT* s, size_type n2);
constexpr basic_string& replace(size_type pos, size_type n, const charT* s);
constexpr basic_string& replace(size_type pos1, size_type n1, size_type n2, charT c);
constexpr basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str);
template<class T>
constexpr basic_string& replace(const_iterator i1, const_iterator i2, const T& t);
constexpr basic_string& replace(const_iterator i1, const_iterator i2, const charT* s, size_type n);
constexpr basic_string& replace(const_iterator i1, const_iterator i2, const charT* s);
constexpr basic_string& replace(const_iterator i1, const_iterator i2, size_type n, charT c);
template<class InputIterator>
constexpr basic_string& replace(const_iterator i1, const_iterator i2,
InputIterator j1, InputIterator j2);
template<container-compatible-range<charT> R>
constexpr basic_string& replace_with_range(const_iterator i1, const_iterator i2, R&& rg);
constexpr basic_string& replace(const_iterator i1, const_iterator i2, initializer_list<charT> il);
constexpr size_type copy(charT* s, size_type n, size_type pos = 0) const;
constexpr void swap(basic_string& s)
noexcept(allocator_traits<Allocator>::propagate_on_container_swap::value ||
allocator_traits<Allocator>::is_always_equal::value);