http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58159
Bug ID: 58159
Summary: unique_ptr::reset should have debug assertion for
"self-reset"
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: gromer at google dot com
unique_ptr::reset() should have a debug assertion for the case that the input
pointer is not null, and is equal to the pointer already stored. This is
virtually always an error: it violates the basic ownership logic of unique_ptr,
and leaves unique_ptr holding a dangling pointer. Strictly speaking, this is
not undefined behavior in itself, but almost any subsequent operation other
than release() (even destroying the unique_ptr) will produce undefined
behavior, so this seems like a highly defensible condition to assert on, at
least in debug mode.
This kind of error is rare, but it does happen; see e.g.
https://code.google.com/p/chromium/issues/detail?id=162971.
