Fixed more Clang warnings

imgui.h

@@ -116,8 +116,8 @@ public:
     inline void                 push_back(const value_type& v)  { if (Size == Capacity) reserve(Capacity ? Capacity * 2 : 4); Data[Size++] = v; }
     inline void                 pop_back()                      { IM_ASSERT(Size > 0); Size--; }
 
-    inline iterator             erase(const_iterator it)        { IM_ASSERT(it >= begin() && it < end()); const ptrdiff_t off = it - begin(); memmove(Data + off, Data + off + 1, (Size - off - 1) * sizeof(value_type)); Size--; return Data + off; }
-    inline void                 insert(const_iterator it, const value_type& v)  { IM_ASSERT(it >= begin() && it <= end()); const ptrdiff_t off = it - begin(); if (Size == Capacity) reserve(Capacity ? Capacity * 2 : 4); if (off < (int)Size) memmove(Data + off + 1, Data + off, (Size - off) * sizeof(value_type)); Data[off] = v; Size++; }
+    inline iterator             erase(const_iterator it)        { IM_ASSERT(it >= begin() && it < end()); const ptrdiff_t off = it - begin(); memmove(Data + off, Data + off + 1, (Size - (size_t)off - 1) * sizeof(value_type)); Size--; return Data + off; }
+    inline void                 insert(const_iterator it, const value_type& v)  { IM_ASSERT(it >= begin() && it <= end()); const ptrdiff_t off = it - begin(); if (Size == Capacity) reserve(Capacity ? Capacity * 2 : 4); if (off < (int)Size) memmove(Data + off + 1, Data + off, (Size - (size_t)off) * sizeof(value_type)); Data[off] = v; Size++; }
 };
 #endif // #ifndef ImVector