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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134554 91177308-0d34-0410-b5e6-96231b3b80d8
- 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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79433 91177308-0d34-0410-b5e6-96231b3b80d8
