std::make_heap is currently implemented by iteratively applying a
siftup-type algorithm. Since sift-up is O(ln n), this gives
std::make_heap a worst case time complexity of O(n ln n).
The C++ standard mandates that std::make_heap make no more than O(3n)
comparisons, this makes our std::make_heap out of spec.
Fix this by introducing an implementation of __sift_down and switch
std::make_heap to create the heap using it.
This gives std::make_heap linear time complexity in the worst case.
This fixes PR20161.
llvm-svn: 213615
Summary:
This patch adds the `<experimental/utility>` header as specified in the latest draft of the library fundamentals TS.
`<experimental/utility>` only contains `class erased_type`.
This patch also updates the documentation to list the `erased_type` class as "initial implementation complete".
Test Plan:
Three test cases where added:
1. Test that `_LIBCPP_VERSION` is defined.
2. Test that `<utility>` has been included.
3. Test that `erased_type` is in the correct namespace and is constexpr default constructible.
Reviewers: mclow.lists
Reviewed By: mclow.lists
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4510
llvm-svn: 213226
Mark the base classes for time_get_byname and time_get as _LIBCPP_TYPE_VIS_ONLY
rather than _LIBCPP_TYPE_VIS. These base classes are templated types and cannot
be stored with export dll storage.
Fixes compilation with _LIBCPP_DLL for Windows when the time_get and
time_get_byname classes are used.
llvm-svn: 213116
Signals may result in nanosleep returning with only some of the
requested sleeping performed.
Utilize nanosleep's "time-remaining" out parameter to continue sleeping
when this occurs.
llvm-svn: 210210
libc++ currently relies on undefined initialization order of global
initializers when using gcc:
1. __start_std_streams in iostream.cpp calls locale:🆔:_init, which assigns
an id to each locale::facet in an initializer
2. Every facet has a static locale::id id, whose constructor sets the facet's
id to 0
If 2 runs after 1, it clobbers the facet's assigned consecutive id, causing
exceptions to be thrown when e.g. running code like "cout << endl".
To fix this, let _LIBCPP_CONSTEXPR evaluate to "constexpr" instead of nothing
with gcc. locale::id's constructor is marked _LIBCPP_CONSTEXPR, which ensures
that it won't get an initializer that could potentially run after the
iostream.cpp initializer. (This remains broken when building with msvc.)
Also switch constexpr-specific code in bitset to use __SIZEOF_SIZE_T__ instead
of __SIZE_WIDTH__, because gcc doesn't define the latter.
Pair-programmed/debugged with Dana Jansens.
llvm-svn: 210188
Make sure we appropriately retry calls to read if the return result is
less than what we asked for.
Additionally, check and handle IO errors: EINTR results in the read
operation getting restarted; other errors turn into exceptions.
llvm-svn: 210061
random_device::random_device(const string&) wrongly assumes that open
can only validly return a file descriptor greater than zero.
This results in random_device believing that it didn't successfully open
the device causing it to throw in it's constructor, this ends up leaking
a file descriptor.
The fix is simple, don't error on file descriptors which are zero.
llvm-svn: 210060
Other tests in this directory use this type, so it's probably copypasta from
there.
(test_buf only forwards to the superclass in all tests where it's used though,
so I wonder if it can be replaced with just using filebuf / wfilebuf
everywhere?)
llvm-svn: 210019
(clang doesn't complain about this, but gcc does. This is necessary for a
follow-up patch that will enable _LIBCPP_CONSTEXPR for gcc.)
llvm-svn: 209888
[syserr.errcat.objects]p4 specifies that
system_category().default_error_condition(ev) map to
error_condition(posv, generic_category()) if ev could map to a POSIX
errno.
Linux reserves up to and including 4095 for errno values, use this as a
bound.
This fixes syserr.errcat.objects/system_category.pass.cpp on Linux.
llvm-svn: 209795
Marshall Clow