Make std::vector<bool> iterator operators friend inline

[Jonathan Wakely]

On 12/10/18 18:25 +0200, François Dumont wrote:
>Here is the patch for _Bit_iterator and _Bit_const_iterator operators.
>
>I noticed that _Bit_reference == and < operators could be made inline 
>friend too. Do you want me to include this change in the patch ?
>
>
>Â Â Â  * include/bits/stl_bvector.h (_Bit_iterator_base::operator==): Replace
>Â Â Â  member method with inline friend.
>Â Â Â  (_Bit_iterator_base::operator<): Likewise.
>Â Â Â  (_Bit_iterator_base::operator!=): Likewise.
>Â Â Â  (_Bit_iterator_base::operator>): Likewise.
>Â Â Â  (_Bit_iterator_base::operator<=): Likewise.
>Â Â Â  (_Bit_iterator_base::operator>=): Likewise.
>Â Â Â  (operator-(const _Bit_iterator_base&, const _Bit_iterator_base&)): Make
>Â Â Â  inline friend.
>Â Â Â  (_Bit_iterator::operator+(difference_type)): Replace member method with
>Â Â Â  inline friend.
>Â Â Â  (_Bit_iterator::operator-(difference_type)): Likewise.
>Â Â Â  (operator+(ptrdiff_t, const _Bit_iterator&)): Make inline friend.
>Â Â Â  (_Bit_const_iterator::operator+(difference_type)): Replace member 
>method
>Â Â Â  with inline friend.
>Â Â Â  (_Bit_const_iterator::operator-(difference_type)): Likewise.
>Â Â Â  (operator+(ptrdiff_t, const _Bit_const_iterator&)): Make inline
>Â Â Â  friend.
>
>Tested under Linux x86_64.
>
>Ok to commit ?
>
>François
>

>diff --git a/libstdc++-v3/include/bits/stl_bvector.h b/libstdc++-v3/include/bits/stl_bvector.h
>index 19c16839cfa..8fbef7a1a3a 100644
>--- a/libstdc++-v3/include/bits/stl_bvector.h
>+++ b/libstdc++-v3/include/bits/stl_bvector.h
>@@ -182,40 +182,40 @@ _GLIBCXX_BEGIN_NAMESPACE_CONTAINER
>       _M_offset = static_cast<unsigned int>(__n);
>     }
> 
>-    bool
>-    operator==(const _Bit_iterator_base& __i) const
>-    { return _M_p == __i._M_p && _M_offset == __i._M_offset; }
>+    friend bool
>+    operator==(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>+    { return __x._M_p == __y._M_p && __x._M_offset == __y._M_offset; }
> 
>-    bool
>-    operator<(const _Bit_iterator_base& __i) const
>+    friend bool
>+    operator<(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>     {
>-      return _M_p < __i._M_p
>-	    || (_M_p == __i._M_p && _M_offset < __i._M_offset);
>+      return __x._M_p < __y._M_p
>+	    || (__x._M_p == __y._M_p && __x._M_offset < __y._M_offset);
>     }
> 
>-    bool
>-    operator!=(const _Bit_iterator_base& __i) const
>-    { return !(*this == __i); }
>+    friend bool
>+    operator!=(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>+    { return !(__x == __y); }
> 
>-    bool
>-    operator>(const _Bit_iterator_base& __i) const
>-    { return __i < *this; }
>+    friend bool
>+    operator>(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>+    { return __y < __x; }
> 
>-    bool
>-    operator<=(const _Bit_iterator_base& __i) const
>-    { return !(__i < *this); }
>+    friend bool
>+    operator<=(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>+    { return !(__y < __x); }
> 
>-    bool
>-    operator>=(const _Bit_iterator_base& __i) const
>-    { return !(*this < __i); }
>-  };
>+    friend bool
>+    operator>=(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>+    { return !(__x < __y); }
> 
>-  inline ptrdiff_t
>-  operator-(const _Bit_iterator_base& __x, const _Bit_iterator_base& __y)
>-  {
>-    return (int(_S_word_bit) * (__x._M_p - __y._M_p)
>-	    + __x._M_offset - __y._M_offset);
>-  }

For the non-member operator- and operator+ this change makes sense,
but what is the benefit of changing all the others? As members they're
already not considered as candidates for unrelated types, or am I
missing something?