vec.insert(vec.begin(), vec[3]);
The issue was that vec[3] returns a reference into the vector, which is invalidated when insert() memmove's the elements down to make space. The method needs to specifically detect and handle this case to correctly match std::vector's semantics.
Thanks to Howard Hinnant for clarifying the correct behavior, and explaining how std::vector solves this problem.
llvm-svn: 134554
- These allow clients to make use of the extra elements in the vector which
have already been allocated, without requiring them to be value initialized.
llvm-svn: 79433
