Author: ericwf Date: Tue Jun 14 20:53:32 2016 New Revision: 272747 URL: http://llvm.org/viewvc/llvm-project?rev=272747&view=rev Log: [libcxx] [test] In test/support/test_allocator.h, fix construct() to avoid moving immovable types.
Summary: In test/support/test_allocator.h, fix construct() to avoid moving immovable types. This improves the allocator's conformance, and fixes compiler errors with MSVC's STL. The scenario is when the allocator is asked to construct an object of type X that's immovable (deleted copy/move ctors), but implicitly constructible from an argument type A. When perfectly forwarded, X can be (explicitly) constructed from A, and everything is fine. That's std::allocator's behavior, and the Standard's default when a user allocator's construct() doesn't exist. The previous implementation of construct() here mishandled this scenario. Passing A to this construct() would implicitly construct an X temporary, bound to (non-templated) T&&. Then construct() would attempt to move-construct X from that X temporary, but X is immovable, boom. Reviewers: mclow.lists, EricWF Subscribers: cfe-commits Differential Revision: http://reviews.llvm.org/D21094 Modified: libcxx/trunk/test/support/test_allocator.h Modified: libcxx/trunk/test/support/test_allocator.h URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/support/test_allocator.h?rev=272747&r1=272746&r2=272747&view=diff ============================================================================== --- libcxx/trunk/test/support/test_allocator.h (original) +++ libcxx/trunk/test/support/test_allocator.h Tue Jun 14 20:53:32 2016 @@ -80,14 +80,14 @@ public: {assert(data_ >= 0); --alloc_count; ::operator delete((void*)p);} size_type max_size() const throw() {return UINT_MAX / sizeof(T);} +#if TEST_STD_VER < 11 void construct(pointer p, const T& val) - {::new(p) T(val);} -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - void construct(pointer p, T&& val) - {::new(p) T(std::move(val));} -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES + {::new(static_cast<void*>(p)) T(val);} +#else + template <class U> void construct(pointer p, U&& val) + {::new(static_cast<void*>(p)) T(std::forward<U>(val));} +#endif void destroy(pointer p) {p->~T();} - friend bool operator==(const test_allocator& x, const test_allocator& y) {return x.data_ == y.data_;} friend bool operator!=(const test_allocator& x, const test_allocator& y) @@ -140,12 +140,13 @@ public: {assert(data_ >= 0); --alloc_count; ::operator delete((void*)p); } size_type max_size() const throw() {return UINT_MAX / sizeof(T);} +#if TEST_STD_VER < 11 void construct(pointer p, const T& val) - {::new(p) T(val);} -#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES - void construct(pointer p, T&& val) - {::new(p) T(std::move(val));} -#endif // _LIBCPP_HAS_NO_RVALUE_REFERENCES + {::new(static_cast<void*>(p)) T(val);} +#else + template <class U> void construct(pointer p, U&& val) + {::new(static_cast<void*>(p)) T(std::forward<U>(val));} +#endif void destroy(pointer p) {p->~T();} friend bool operator==(const non_default_test_allocator& x, const non_default_test_allocator& y) _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
