[libc++][NFC] Use _LIBCPP_DEBUG_ASSERT in <string>

[philnik]

Summary

Use _LIBCPP_DEBUG_ASSERT instead of _LIBCPP_ASSERT and guarding it with LIBCPP_DEBUG_LEVEL == 2

libcxx/include/string

 template<class _InputIterator>
 __enable_if_t
 <
    __is_exactly_cpp17_input_iterator<_InputIterator>::value,
    typename basic_string<_CharT, _Traits, _Allocator>::iterator
 >
 basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _InputIterator __first, _InputIterator __last)
 {
-#if _LIBCPP_DEBUG_LEVEL == 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
+  _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
                        "string::insert(iterator, range) called with an iterator not"
                        " referring to this string");
-#endif
-    const basic_string __temp(__first, __last, __alloc());
-    return insert(__pos, __temp.data(), __temp.data() + __temp.size());
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 template<class _ForwardIterator>
 __enable_if_t
 <
     __is_cpp17_forward_iterator<_ForwardIterator>::value,
     typename basic_string<_CharT, _Traits, _Allocator>::iterator
 >
 basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last)
 {
-#if _LIBCPP_DEBUG_LEVEL == 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
+  _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
                        "string::insert(iterator, range) called with an iterator not"
                        " referring to this string");
-#endif
+
     size_type __ip = static_cast<size_type>(__pos - begin());
     size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
     if (__n)
     {
         if (__string_is_trivial_iterator<_ForwardIterator>::value &&
             !__addr_in_range(*__first))
         {
             size_type __sz = size();
basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c)
     return begin() + static_cast<difference_type>(__ip);
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 inline
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
 {
-#if _LIBCPP_DEBUG_LEVEL == 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
+  _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");
-#endif
-    difference_type __p = __pos - begin();
-    insert(static_cast<size_type>(__p), __n, __c);
-    return begin() + __p;
 }
 
 // replace
 
 template <class _CharT, class _Traits, class _Allocator>
 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>::erase(size_type __pos,
   return *this;
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 inline
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos)
 {
-#if _LIBCPP_DEBUG_LEVEL == 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
+  _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
                        "string::erase(iterator) called with an iterator not"
                        " referring to this string");
-#endif
-    _LIBCPP_ASSERT(__pos != end(),
-        "string::erase(iterator) called with a non-dereferenceable iterator");
-    iterator __b = begin();
-    size_type __r = static_cast<size_type>(__pos - __b);
-    erase(__r, 1);
-    return __b + static_cast<difference_type>(__r);
+
+  _LIBCPP_ASSERT(__pos != end(), "string::erase(iterator) called with a non-dereferenceable iterator");
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 inline
 typename basic_string<_CharT, _Traits, _Allocator>::iterator
 basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last)
 {
-#if _LIBCPP_DEBUG_LEVEL == 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
+  _LIBCPP_DEBUG_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
                        "string::erase(iterator,  iterator) called with an iterator not"
                        " referring to this string");
-#endif
-    _LIBCPP_ASSERT(__first <= __last, "string::erase(first, last) called with invalid range");
-    iterator __b = begin();
-    size_type __r = static_cast<size_type>(__first - __b);
-    erase(__r, static_cast<size_type>(__last - __first));
-    return __b + static_cast<difference_type>(__r);
+
 }
 
 template <class _CharT, class _Traits, class _Allocator>
 inline
 void
 basic_string<_CharT, _Traits, _Allocator>::pop_back()
 {
     _LIBCPP_ASSERT(!empty(), "string::pop_back(): string is already empty");