Fix truncation warnings in string/vector iterator subtraction and…

… `ranges::is_permutation` (#4237)
microsoft · Dec 7, 2023 · ae50dff · ae50dff
1 parent b351b67
commit ae50dff
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Showing 3 changed files with 4 additions and 3 deletions.
diff --git a/stl/inc/algorithm b/stl/inc/algorithm
@@ -937,7 +937,8 @@ namespace ranges {
             if constexpr (bidirectional_iterator<_It1> && bidirectional_iterator<_It2>) {
                 // determine final iterator values
                 auto _Final1 = _RANGES _Find_last_iterator(_First1, _Last1, _Count);
-                auto _Final2 = _RANGES _Find_last_iterator(_First2, _Last2, _Count);
+                using _Diff2 = iter_difference_t<_It2>; // avoid truncation warnings; ranges are the same length
+                auto _Final2 = _RANGES _Find_last_iterator(_First2, _Last2, static_cast<_Diff2>(_Count));
 
                 for (;;) { // trim matching suffixes
                     --_Final1;

diff --git a/stl/inc/vector b/stl/inc/vector
@@ -154,7 +154,7 @@ public:
 
     _NODISCARD _CONSTEXPR20 difference_type operator-(const _Vector_const_iterator& _Right) const noexcept {
         _Compat(_Right);
-        return _Ptr - _Right._Ptr;
+        return static_cast<difference_type>(_Ptr - _Right._Ptr);
     }
 
     _NODISCARD _CONSTEXPR20 reference operator[](const difference_type _Off) const noexcept {

diff --git a/stl/inc/xstring b/stl/inc/xstring
@@ -1969,7 +1969,7 @@ public:
 
     _NODISCARD _CONSTEXPR20 difference_type operator-(const _String_const_iterator& _Right) const noexcept {
         _Compat(_Right);
-        return _Ptr - _Right._Ptr;
+        return static_cast<difference_type>(_Ptr - _Right._Ptr);
     }
 
     _NODISCARD _CONSTEXPR20 reference operator[](const difference_type _Off) const noexcept {