basic_string& insert(size_type pos, const basic_string& str);
basic_string& insert(size_type pos1, const basic_string& str, size_type pos2, size_type n = npos);
template<class T>
basic_string& insert(size_type pos, const T& t);
{ basic_string_view<charT, traits> sv = t; return insert(pos, sv.data(), sv.size()); }
template<class T>
basic_string& insert(size_type pos1, const T& t, size_type pos2, size_type n = npos);
basic_string& insert(size_type pos, const charT* s, size_type n);
basic_string& insert(size_type pos, const charT* s);
basic_string& insert(size_type pos, size_type n, charT c);
iterator insert(const_iterator p, charT c);
iterator insert(const_iterator p, size_type n, charT c);
template<class InputIterator>
iterator insert(const_iterator p, InputIterator first, InputIterator last);
iterator insert(const_iterator p, initializer_list<charT> il);