[libc++] inline more functions into basic_string

[philnik]

Summary

This removes a lot of boilerplate.

[ldionne]

Can you run benchmarks for string before and after just to be sure? It shouldn't change anything since the functions were inline before and they still are implicitly inline, but who knows.

[EricWF]

This also affects external instantiations. So I'm not sure this is as simple as just "removing boilerplate".

Have you considered this?

[EricWF]

Disregard me. They were all marked inline already.

Though I must say, I prefer out-of-line definitions for big classes because it makes it easier to inspect the class and see we provide the correct declarations.

libcxx/include/string

#endif // _LIBCPP_CXX03_LANG
     template <class _Tp, class = __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
                                                !__is_same_uncvref<_Tp, basic_string>::value> >
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(const _Tp& __t) {
       __self_view __sv = __t;
       return assign(__sv);
     }
 
 #ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& operator=(basic_string&& __str)
-        _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(basic_string&& __str)
+      _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value)) {
+    __move_assign(__str, integral_constant<bool, __alloc_traits::propagate_on_container_move_assignment::value>());
+    return *this;
+  }
+
      _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& operator=(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
 #endif
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& operator=(const value_type* __s) {return assign(__s);}
 #if _LIBCPP_STD_VER > 20
     basic_string& operator=(nullptr_t) = delete;
 #endif
const_reverse_iterator crbegin() const _NOEXCEPT
         {return rbegin();}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     const_reverse_iterator crend() const _NOEXCEPT
         {return rend();}
 
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type size() const _NOEXCEPT
         {return __is_long() ? __get_long_size() : __get_short_size();}
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type length() const _NOEXCEPT {return size();}
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type max_size() const _NOEXCEPT;
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type max_size() const _NOEXCEPT {
+    size_type __m = __alloc_traits::max_size(__alloc());
+    if (__m <= std::numeric_limits<size_type>::max() / 2) {
+      return __m - __alignment;
+    } else {
+    bool __uses_lsb = __endian_factor == 2;
+      return __uses_lsb ? __m - __alignment : (__m / 2) - __alignment;
+    }
+  }
+
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type capacity() const _NOEXCEPT {
         return (__is_long() ? __get_long_cap() : static_cast<size_type>(__min_cap)) - 1;
     }
 
     _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n, value_type __c);
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void resize(size_type __n) { resize(__n, value_type()); }
 
     _LIBCPP_CONSTEXPR_SINCE_CXX20 void reserve(size_type __requested_capacity);
#endif
 
     _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_HIDE_FROM_ABI void reserve() _NOEXCEPT { shrink_to_fit(); }
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void shrink_to_fit() _NOEXCEPT;
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void clear() _NOEXCEPT;
 
     _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     bool empty() const _NOEXCEPT {return size() == 0;}
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    const_reference operator[](size_type __pos) const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference operator[](size_type __pos) _NOEXCEPT;
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference operator[](size_type __pos) const _NOEXCEPT {
+    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
+    return *(data() + __pos);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference operator[](size_type __pos) _NOEXCEPT {
+    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
+    return *(__get_pointer() + __pos);
+  }
 
     _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference at(size_type __n) const;
     _LIBCPP_CONSTEXPR_SINCE_CXX20 reference       at(size_type __n);
 
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const basic_string& __str) {
         return append(__str);
     }
 
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(value_type __c) {
         return *this;
     }
 
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& operator+=(initializer_list<value_type> __il) { return append(__il); }
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& append(const basic_string& __str);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const basic_string& __str) {
+        return append(__str.data(), __str.size());
+  }
 
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t<
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value
             && !__is_same_uncvref<_Tp, basic_string>::value,
             basic_string&
         >

 
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& append(initializer_list<value_type> __il) {return append(__il.begin(), __il.size());}
 #endif // _LIBCPP_CXX03_LANG
 
     _LIBCPP_CONSTEXPR_SINCE_CXX20 void push_back(value_type __c);
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void pop_back();
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference       front() _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference front() const _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference       back() _NOEXCEPT;
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference back() const _NOEXCEPT;
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference front() _NOEXCEPT {
+    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
+    return *__get_pointer();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference front() const _NOEXCEPT {
+    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
+    return *data();
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference back() _NOEXCEPT {
+    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
+    return *(__get_pointer() + size() - 1);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 const_reference back() const _NOEXCEPT {
+    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
+    return *(data() + size() - 1);
+  }
 
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
__enable_if_t
             basic_string&
         >
         assign(_ForwardIterator __first, _ForwardIterator __last);
 #ifndef _LIBCPP_CXX03_LANG
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& assign(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
 #endif // _LIBCPP_CXX03_LANG
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& insert(size_type __pos1, const basic_string& __str);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  insert(size_type __pos1, const basic_string& __str) {
+    return insert(__pos1, __str.data(), __str.size());
+  }
 
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
__enable_if_t
         >
                   insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n=npos);
     _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n=npos);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, const value_type* __s);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& insert(size_type __pos, size_type __n, value_type __c);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator      insert(const_iterator __pos, value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    iterator      insert(const_iterator __pos, size_type __n, value_type __c);
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 iterator
+  insert(const_iterator __pos, size_type __n, value_type __c) {
+    _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
+                         "string::insert(iterator, n, value) called with an iterator not referring to this string");
+    difference_type __p = __pos - begin();
+    insert(static_cast<size_type>(__p), __n, __c);
+    return begin() + __p;
+  }
+
     template<class _InputIterator>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __is_exactly_cpp17_input_iterator<_InputIterator>::value,
             iterator
         >
         insert(const_iterator __pos, _InputIterator __first, _InputIterator __last);

 #endif // _LIBCPP_CXX03_LANG
 
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& erase(size_type __pos = 0, size_type __n = npos);
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     iterator      erase(const_iterator __pos);
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     iterator      erase(const_iterator __first, const_iterator __last);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  replace(size_type __pos1, size_type __n1, const basic_string& __str) {
+    return replace(__pos1, __n1, __str.data(), __str.size());
+  }
 
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
                   replace(size_type __pos1, size_type __n1, const _Tp& __t) { __self_view __sv = __t; return replace(__pos1, __n1, __sv.data(), __sv.size()); }
     _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos);
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value  && !__is_same_uncvref<_Tp, basic_string>::value,
             basic_string&
         >
                   replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2=npos);
     _LIBCPP_CONSTEXPR_SINCE_CXX20
     basic_string& replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const basic_string& __str);
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  replace(const_iterator __i1, const_iterator __i2, const basic_string& __str) {
+    return replace(
+        static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __str.data(), __str.size());
+  }
 
     template <class _Tp>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
             basic_string&
         >
                   replace(const_iterator __i1, const_iterator __i2, const _Tp& __t) { __self_view __sv = __t; return replace(__i1 - begin(), __i2 - __i1, __sv); }
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s);
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    basic_string& replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n) {
+    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  replace(const_iterator __i1, const_iterator __i2, const value_type* __s) {
+    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
+  replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c) {
+    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
+  }
+
     template<class _InputIterator>
     _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS _LIBCPP_CONSTEXPR_SINCE_CXX20
     __enable_if_t
         <
             __is_cpp17_input_iterator<_InputIterator>::value,
             basic_string&
         >
         replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2);
void __grow_by_and_replace(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
                                size_type __n_add, const value_type* __p_new_stuff);
 
     // __assign_no_alias is invoked for assignment operations where we
     // have proof that the input does not alias the current instance.
     // For example, operator=(basic_string) performs a 'self' check.
     template <bool __is_short>
     _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& __assign_no_alias(const value_type* __s, size_type __n);
 
-    _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
-    void __erase_to_end(size_type __pos);
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 void __erase_to_end(size_type __pos) {
+    __null_terminate_at(std::__to_address(__get_pointer()), __pos);
+  }
 
     // __erase_external_with_move is invoked for erase() invocations where
     // `n ~= npos`, likely requiring memory moves on the string data.
     _LIBCPP_CONSTEXPR_SINCE_CXX20 void __erase_external_with_move(size_type __pos, size_type __n);
 
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     void __copy_assign_alloc(const basic_string& __str)
         {__copy_assign_alloc(__str, integral_constant<bool,
#endif
   if (__libcpp_is_constant_evaluated()) {
     __str.__default_init();
   } else {
     __str.__set_short_size(0);
     traits_type::assign(__str.__get_short_pointer()[0], value_type());
   }
 }
 
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
-    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
-{
-    __move_assign(__str, integral_constant<bool,
-          __alloc_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
 #endif
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _InputIterator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 __enable_if_t
 <
      __is_exactly_cpp17_input_iterator<_InputIterator>::value,
if (__n)
             const basic_string __temp(__first, __last, __alloc());
             append(__temp.data(), __temp.size());
         }
     }
     return *this;
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str)
-{
-    return append(__str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n)
 {
     size_type __sz = __str.size();
     if (__pos > __sz)
         __throw_out_of_range();
     return append(__str.data() + __pos, std::min(__n, __sz - __pos));
basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last)
     else
     {
         const basic_string __temp(__first, __last, __alloc());
         return __insert_from_safe_copy(__n, __ip, __temp.begin(), __temp.end());
     }
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str)
-{
-    return insert(__pos1, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str,
                                                   size_type __pos2, size_type __n)
 {
     size_type __str_sz = __str.size();
     if (__pos2 > __str_sz)
         __throw_out_of_range();
else
             traits_type::move(__p + __ip + 1, __p + __ip, __n_move);
     }
     traits_type::assign(__p[__ip], __c);
     traits_type::assign(__p[++__sz], value_type());
     __set_size(__sz);
     return begin() + static_cast<difference_type>(__ip);
 }
 
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::iterator
-basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
-{
-  _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
-                       "string::insert(iterator, n, value) called with an iterator not"
-                       " referring to this string");
-  difference_type __p = __pos - begin();
-  insert(static_cast<size_type>(__p), __n, __c);
-  return begin() + __p;
-}
-
 // replace
 
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
 {

 basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2,
                                                    _InputIterator __j1, _InputIterator __j2)
 {
     const basic_string __temp(__j1, __j2, __alloc());
     return replace(__i1, __i2, __temp);
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str)
-{
-    return replace(__pos1, __n1, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str,
                                                    size_type __pos2, size_type __n2)
 {
     size_type __str_sz = __str.size();
     if (__pos2 > __str_sz)
         __throw_out_of_range();

 _LIBCPP_CONSTEXPR_SINCE_CXX20
 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s)
 {
     _LIBCPP_ASSERT(__s != nullptr, "string::replace received nullptr");
     return replace(__pos, __n1, __s, traits_type::length(__s));
 }
 
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const basic_string& __str)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1),
-                   __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
-}
-
 // erase
 
 // 'externally instantiated' erase() implementation, called when __n != npos.
 // Does not check __pos against size()
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::__erase_external_with_move(
basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT
     else
     {
         traits_type::assign(*__get_short_pointer(), value_type());
         __set_short_size(0);
     }
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-void
-basic_string<_CharT, _Traits, _Allocator>::__erase_to_end(size_type __pos)
-{
-  __null_terminate_at(std::__to_address(__get_pointer()), __pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c)
 {
     size_type __sz = size();
     if (__n > __sz)
         append(__n - __sz, __c);
     else
         __erase_to_end(__n);
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 inline void
 basic_string<_CharT, _Traits, _Allocator>::__resize_default_init(size_type __n)
 {
     size_type __sz = size();
     if (__n > __sz) {
        __append_default_init(__n - __sz);
     } else
         __erase_to_end(__n);
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::max_size() const _NOEXCEPT
-{
-    size_type __m = __alloc_traits::max_size(__alloc());
-    if (__m <= std::numeric_limits<size_type>::max() / 2) {
-        return __m - __alignment;
-    } else {
-        bool __uses_lsb = __endian_factor == 2;
-        return __uses_lsb ? __m - __alignment : (__m / 2) - __alignment;
-    }
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 void
 basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __requested_capacity)
 {
     if (__requested_capacity > max_size())
         __throw_length_error();
 
     // Make sure reserve(n) never shrinks. This is technically only required in C++20
if (__now_long)
         __set_long_pointer(__new_data);
     }
     else
         __set_short_size(__sz);
     std::__debug_db_invalidate_all(this);
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
-    return *(data() + __pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
-    return *(__get_pointer() + __pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::const_reference
 basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const
 {
     if (__n >= size())
         __throw_out_of_range();
     return (*this)[__n];
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::reference
 basic_string<_CharT, _Traits, _Allocator>::at(size_type __n)
 {
     if (__n >= size())
         __throw_out_of_range();
     return (*this)[__n];
 }
 
 template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::front() _NOEXCEPT
-{
-    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
-    return *__get_pointer();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::front() const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
-    return *data();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::back() _NOEXCEPT
-{
-    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
-    return *(__get_pointer() + size() - 1);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_CONSTEXPR_SINCE_CXX20
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::back() const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
-    return *(data() + size() - 1);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20
 typename basic_string<_CharT, _Traits, _Allocator>::size_type
 basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const
 {
     size_type __sz = size();
     if (__pos > __sz)
         __throw_out_of_range();
     size_type __rlen = std::min(__n, __sz - __pos);