Summary:
Added IsBits (has value semantics; can be copied by memcpy and
deleted by free. Implies IsRelocatable) and Is0Initializable (new (ptr)
T() is equivalent to memset(ptr, 0, sizeof(T))).
Converted the boost types for IsRelocatable to std types (now available
from <type_traits>).
Added a new way to specify IsRelocatable, IsBits, and Is0Initializable:
typedef std::true_type <property-name> in your class. No namespace
exiting required. This method also supports inheritance, and may be
overriden in base classes.
Added a test file to test Traits.

Test Plan:
Run new test file. Compile some real-world code (in my case,
multifeed).

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D610996

Summary: I forgot fbmake runtests doesn't build all that's configured, oops.

Test Plan: Build folly/experimental/test, run benchmark.

Reviewed By: tudorb@fb.com

FB internal diff: D647191

Summary:
It makes sense to return subpiece of the original data
from ##rest()##.

Test Plan: gv tests

Reviewed By: soren@fb.com

FB internal diff: D647179

Summary:
It was previously breaking any time a generator included a comma, which
is pretty stupid. Now, it's modelled after `ScopeGuard`, using a little operator
overloading to get rid of the trailing `)` and sidestepping preprocessor issues.

Test Plan: Unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D646825

Summary:
Code that aids in storing data aligned on block (possibly cache-line)
boundaries, perhaps with padding. There's class Node which represents one
block, and Iterator which, given an iterator to a container of Nodes, gives you
an iterator to the underlying elements.  There's also Adaptor, which converts a
sequence of Node into a sequence of underlying elements. (with enough
functionality to make it useful, although it's not fully STL compatible)

Split off from https://phabricator.fb.com/D641114

Also includes changes to make TypedIOBuf container-like so it can be used with padded_sequence::Adaptor.

I plan to rename this to Padded.h / folly::padded in a separate diff.

Test Plan: test added

Reviewed By: soren@fb.com

FB internal diff: D646249

Summary:
I noticed that push_back(Char) was slower for fbstring than
for std::string for long strings and found that I could make
it faster by inlining the call to mutable_data() and
exploit that it's always non-small and non-shared.

Benchmarks before:

./folly/test/FBStringTestBenchmarks.cpp.h       relative  time/iter  iters/s
BM_push_back_string(1)                                      69.42ns   14.41M
BM_push_back_string(23)                                    582.31ns    1.72M
BM_push_back_string(127)                                     1.47us  682.12K
BM_push_back_string(1024)                                    5.52us  181.07K
BM_push_back_fbstring(1)                                     9.55ns  104.74M
BM_push_back_fbstring(23)                                  212.45ns    4.71M
BM_push_back_fbstring(127)                                 864.00ns    1.16M
BM_push_back_fbstring(1024)                                  6.73us  148.52K

and after:

BM_push_back_fbstring(1)                                     9.55ns  104.74M
BM_push_back_fbstring(23)                                  212.45ns    4.71M
BM_push_back_fbstring(127)                                 783.08ns    1.28M
BM_push_back_fbstring(1024)                                  4.03us  248.05K

Test Plan: fbconfig folly/test && fbmake runtests

Reviewed By: tudorb@fb.com

FB internal diff: D646081

Summary:
Added closing curly braces at 173.
Sorry, must make diff if it's a new commit.

Test Plan: nothing really

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D644925

Summary: Added two samples of use for FBVector in docs

Test Plan: just check if FBVector.md looks good.

Reviewed By: njormrod@fb.com

FB internal diff: D636813

Summary:
This code is not strictly correct per c++ spec section 14.2.4:

> When the name of a member template specialization appears after . or -> in a
> postfix-expression or after a nested-name-specifier in a qualified-id, and the
> object or pointer expression of the postfix-expression or the
> nested-name-specifier in the qualified-id depends on a template parameter
> (14.6.2) but does not refer to a member of the current instantiation
> (14.6.2.1), the member template name must be prefixed by the keyword template.
> Otherwise the name is assumed to name a non-template.

This causes clang to complain, but gcc is lax about this, as usual.

Test Plan: compile stuff that use this.

Reviewed By: delong.j@fb.com

FB internal diff: D643515

Summary:
the old code is ill-formed per spec (section 14.6.8):

> If a type used in a non-dependent name is incomplete at the point at which a
> template is defined but is complete at the point at which an instantiation is
> done, and if the completeness of that type affects whether or not the program
> is well-formed or affects the semantics of the program, the program is
> ill-formed; no diagnostic is required.

GCC is lax and allows this, clang gives an error.

Test Plan: compiles.

Reviewed By: delong.j@fb.com

FB internal diff: D643431

Summary:
curiously, std::out_of_range doesn't have a zero-argument constructor according
to the spec. This was causing issues in my clang setup...

Test Plan: compiles.

Reviewed By: delong.j@fb.com

FB internal diff: D643363

Test Plan: looked at the generated html in a browser

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D642998

Summary:
Added specializations of folly::to<String> for __int128_t
and __uint128_t.

Test Plan: Added tests of the above to the integral to string tests.

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D636992

Summary:
Returns number of bytes "really used by the user", i.e. number of bytes
allocated on the arena via calls to `allocate()`.

Test Plan: compiled, unit tests

Reviewed By: azzolini@fb.com

FB internal diff: D636976

Summary:
Supressing the warning for GCC4.7, and supressing the error supressing
the warning in GCC4.6.

Test Plan: Compile, run unit tests on GCC4.6 and GCC4.7

Reviewed By: ldbrandy@fb.com

FB internal diff: D635982

Summary:
Noticed these TODOs in Conv.h and decided to fix them.
Discovered that the underlying_type implementation also
covers enum classes, which didn't work with the pre-existing code.

Test Plan:
fbconfig -r folly --platform=gcc-4.7.1-glibc-2.14.1-fb
fbmake dbg _bin/folly/test/conv_test
_bin/folly/test/conv_test

--platform=gcc-4.6.2-glibc-2.13
fbmake dbg _bin/folly/test/conv_test
_bin/folly/test/conv_test

Reviewed By: tudorb@fb.com

FB internal diff: D634309

Summary: D633912 broke unicorn because it relied on preallocate having a hard max.  Add an optional hard max parameter and rename maxHint to newAllocationSize.  Pass the hard max in for unicorn

Test Plan: folly and unicorn unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D634894

Summary: IOBufQueue::preallocate currently takes a min and max size, and will return to the caller a buffer with N writable bytes with min <= N <= max.  This is a bit wasteful, since there may be more than max bytes available at the end if the queue with no extra cost.  Now preallocate will return the full amount of contigious space to the caller, even if it is larger than the requested max.

Test Plan: folly and proxygen unit tests

Reviewed By: simpkins@fb.com

FB internal diff: D633912

Summary:
cursor.clone() will clone a length of the chain.  insert(std::move(buf)) will splice in a length of chain
I want this to change thrift2 binary type to IOBuf: we will clone() the network data for zero-copy userspace data, and insert() it if the return value is a IOBuf.

Test Plan: added unittest

Reviewed By: afrind@fb.com

FB internal diff: D632073

Summary:
Add a version of IOBuf::copyBuffer() which accepts a std::string, as
well as a maybeCopyBuffer() function which returns a null pointer if the
input string is empty.

In proxygen we have a few places where we construct an IOBuf from a
string configuration parameter, and we almost always want a null pointer
rather than an empty IOBuf chain if the string is empty.

Test Plan: Included unit tests for these new functions.

Reviewed By: tudorb@fb.com

FB internal diff: D630547

Summary: ##byLine## already yields StringPieces, no neat to ##eachAs()## then.

Test Plan:
fbconfig folly/experimental/symbolizer folly/test folly/experimental/io folly/experimental/io/test tupperware/agent
fbmake opt

Reviewed By: tudorb@fb.com

FB internal diff: D630422

Test Plan: build

Reviewed By: dneiter@fb.com

FB internal diff: D630324

Test Plan: build

Reviewed By: tjackson@fb.com

FB internal diff: D630280

Test Plan: test added

Reviewed By: tjackson@fb.com

FB internal diff: D630163

Test Plan: build

Reviewed By: tjackson@fb.com

FB internal diff: D630266

Summary:
Switch existing code to gen::byLine.  Also fix namespaces in
folly/experimental/(symbolizer|exception_tracer).

Test Plan:
fbconfig -r folly && fbmake runtests_opt, ran non-test folly
binaries by hand, fbgs for other uses (there aren't any)

Reviewed By: tjackson@fb.com

FB internal diff: D629576

Summary: Normal split to complement resplit, and it's a bit faster than folly::split().

Test Plan: Unit tests, Benchmarks (result in code comment)

Reviewed By: tudorb@fb.com

FB internal diff: D629998

Test Plan: no

Reviewed By: tjackson@fb.com

FB internal diff: D629502

Summary:
Also added eachAs (cast each value as a given type) and eachTo (use folly::to
on each value)

Test Plan: test added

Reviewed By: tjackson@fb.com

FB internal diff: D628868

Summary: Make things work with non-copyable generators.

Test Plan: folly/experimental/test

Reviewed By: tjackson@fb.com

FB internal diff: D628520

Summary:
Want to be able to call them from other constexpr functions
and from within static_assert()s.

Test Plan: compiled and ran folly tests

Reviewed By: tudorb@fb.com

FB internal diff: D627413

Summary: That's all.

Test Plan: .

Reviewed By: tjackson@fb.com

FB internal diff: D618824

Summary:
Sometimes it'll be handy to have a custom operator which is little more than the
composition of a few base operators. This makes that really easy to do, as shown
in examples, tests, and benchmarks.

Test Plan: Unit tests, benchmarks

Reviewed By: rsagula@fb.com

FB internal diff: D617152

Summary: We should be able to print ##Foo*##, even if we can't print ##Foo##.

Test Plan: Unit Tests.

Reviewed By: tudorb@fb.com

FB internal diff: D625977

Summary:
If your format string ends up being conditional, it's handy to be able to chain
together formatters.

Test Plan: Unit tests

Reviewed By: tudorb@fb.com

FB internal diff: D625502

Summary:
Convert a IOBuf chain into a fbstring, with zero copies in the common case
(unshared, unchained, no headroom) and one copy in all other cases.

Test Plan: tests added

Reviewed By: simpkins@fb.com

FB internal diff: D621210

Summary: fixing clang errors (used clang 3.1)

Test Plan: doh

Reviewed By: tudorb@fb.com

FB internal diff: D622593

Summary:
Yes, I admit, I was dumb enough to try it in a benchmark's
body.

Test Plan: review

Reviewed By: tudorb@fb.com

FB internal diff: D622613

Summary:
DynamicConverter uses some simple heuristics to determine if a
class is a container. One of those tests was to check that the
constructor 'template <class Iterator> [container-name](Iterator first,
Iterator last)' was present. That test was performed by checking if the
class could be constructed by two parameters of some dummy class.

However, it is possible to restrict the template parameter such that it
only accepts iterators, and not any arbitrary dummy class. This would be
useful, for example, to solve overload ambiguity with constructors like
'vector(const T& val, size_type n)', where T and size_type are the same
(see N3337 23.2.3 item 14). It also (I believe) produces more meaningful
compiler errors when a non-iterator is supplied, since it errors at the
function callsite instead of inside the constructor itself.

The new FBVector implementation uses such a feature, and so checking for
[container-name](dummy, dummy) will fail. Hence the dummy class has been
upgraded to reverse_iterator<T*>, a valid iterator class which almost
certainly does not have a specialized contructor in any class (and hence
will not cause any visible change in class_is_container's value).

Test Plan:
Run DynamicConverterTest; it has tests for the correctness of
class_is_container.

Reviewed By: delong.j@fb.com

FB internal diff: D620607

Summary:
Changed communicate() flags from int to a class.
Made Options and CommunicateFlags composable with |
Simplified API so you don't have to type Subprocess::Options().stdout(Subprocess::PIPE)

Test Plan: subprocess_test

Reviewed By: chip@fb.com

FB internal diff: D620186