[PATCH] D48342: [libcxx] Optimize vectors construction of trivial types from an iterator range with const-ness mismatch.

[Volodymyr Sapsai via Phabricator via cfe-commits]

vsapsai added inline comments.


================
Comment at: libcxx/test/std/containers/sequences/vector/vector.cons/construct_iter_iter.pass.cpp:161
+  {
+    // Though types are different, initialization can be done with `memcpy`.
+    int32_t array[1] = {-1};
----------------
Quuxplusone wrote:
> I might add "can be, but currently isn't, done with memcpy."
> 
> Here's my other suggested test:
> 
> ```
> struct X { int x; };
> struct Y { int y; };
> struct Z : X, Y { int z; };
> {
>     Z z;
>     Z *array[1] = { &z };
>     // Though the types Z* and Y* are very similar, initialization still cannot be done with memcpy.
>     std::vector<Y*> v(array, array + 1);
>     assert(v[0] == &z);
> }
> ```
Thanks, I'll try your `XYZ` test, looks like it should help with my `iostream*/ostream*` struggles.


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  https://reviews.llvm.org/D48342/new/

https://reviews.llvm.org/D48342