While LLVM, Clang, and LLD use C++11, not all features are available in all of
the toolchains which we support. The set of features supported for use in LLVM
-is the intersection of those supported in MSVC 2012, GCC 4.7, and Clang 3.1.
+is the intersection of those supported in MSVC 2013, GCC 4.7, and Clang 3.1.
The ultimate definition of this set is what build bots with those respective
toolchains accept. Don't argue with the build bots. However, we have some
guidance below to help you know what to expect.
* Trailing return types: N2541_
* Lambdas: N2927_
- * But *not* ``std::function``, until Clang implements `MSVC-compatible RTTI`_.
- * And *not* lambdas with default arguments.
+ * But *not* lambdas with default arguments.
* ``decltype``: N2343_
* Nested closing right angle brackets: N1757_
* ``override`` and ``final``: N2928_, N3206_, N3272_
* Atomic operations and the C++11 memory model: N2429_
+* Variadic templates: N2242_
+* Explicit conversion operators: N2437_
+* Defaulted and deleted functions: N2346_
+
+ * But not defaulted move constructors or move assignment operators, MSVC 2013
+ cannot synthesize them.
+* Initializer lists: N2627_
+* Delegating constructors: N1986_
.. _N2118: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2118.html
.. _N2439: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2439.htm
.. _N3206: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3206.htm
.. _N3272: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3272.htm
.. _N2429: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2429.htm
+.. _N2242: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2242.pdf
+.. _N2437: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2437.pdf
+.. _N2346: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2346.htm
+.. _N2627: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2672.htm
+.. _N1986: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1986.pdf
.. _MSVC-compatible RTTI: http://llvm.org/PR18951
The supported features in the C++11 standard libraries are less well tracked,
* While most of the atomics library is well implemented, the fences are
missing. Fortunately, they are rarely needed.
* The locale support is incomplete.
-* ``std::initializer_list`` (and the constructors and functions that take it as
- an argument) are not always available, so you cannot (for example) initialize
- a ``std::vector`` with a braced initializer list.
+* ``std::equal()`` (and other algorithms) incorrectly assert in MSVC when given
+ ``nullptr`` as an iterator.
Other than these areas you should assume the standard library is available and
working as expected until some build bot tells you otherwise. If you're in an
.. _the libstdc++ manual:
http://gcc.gnu.org/onlinedocs/gcc-4.7.3/libstdc++/manual/manual/status.html#status.iso.2011
+Other Languages
+---------------
+
+Any code written in the Go programming language is not subject to the
+formatting rules below. Instead, we adopt the formatting rules enforced by
+the `gofmt`_ tool.
+
+Go code should strive to be idiomatic. Two good sets of guidelines for what
+this means are `Effective Go`_ and `Go Code Review Comments`_.
+
+.. _gofmt:
+ https://golang.org/cmd/gofmt/
+
+.. _Effective Go:
+ https://golang.org/doc/effective_go.html
+
+.. _Go Code Review Comments:
+ https://code.google.com/p/go-wiki/wiki/CodeReviewComments
+
Mechanical Source Issues
========================
file is released under. This makes it perfectly clear what terms the source
code can be distributed under and should not be modified in any way.
-The main body is a ``doxygen`` comment describing the purpose of the file. It
+The main body is a ``doxygen`` comment (identified by the ``///`` comment
+marker instead of the usual ``//``) describing the purpose of the file. It
should have a ``\brief`` command that describes the file in one or two
sentences. Any additional information should be separated by a blank line. If
an algorithm is being implemented or something tricky is going on, a reference
Comment Formatting
^^^^^^^^^^^^^^^^^^
-In general, prefer C++ style (``//``) comments. They take less space, require
+In general, prefer C++ style comments (``//`` for normal comments, ``///`` for
+``doxygen`` documentation comments). They take less space, require
less typing, don't have nesting problems, etc. There are a few cases when it is
useful to use C style (``/* */``) comments however:
// Bar isn't POD, but it does look like a struct.
struct Bar {
int Data;
- Foo() : Data(0) { }
+ Bar() : Data(0) { }
};
Do not use Braced Initializer Lists to Call a Constructor
individual enumerators. To suppress this warning, use ``llvm_unreachable`` after
the switch.
-Use ``LLVM_DELETED_FUNCTION`` to mark uncallable methods
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-Prior to C++11, a common pattern to make a class uncopyable was to declare an
-unimplemented copy constructor and copy assignment operator and make them
-private. This would give a compiler error for accessing a private method or a
-linker error because it wasn't implemented.
-
-With C++11, we can mark methods that won't be implemented with ``= delete``.
-This will trigger a much better error message and tell the compiler that the
-method will never be implemented. This enables other checks like
-``-Wunused-private-field`` to run correctly on classes that contain these
-methods.
-
-For compatibility with MSVC, ``LLVM_DELETED_FUNCTION`` should be used which
-will expand to ``= delete`` on compilers that support it. These methods should
-still be declared private. Example of the uncopyable pattern:
-
-.. code-block:: c++
-
- class DontCopy {
- private:
- DontCopy(const DontCopy&) LLVM_DELETED_FUNCTION;
- DontCopy &operator =(const DontCopy&) LLVM_DELETED_FUNCTION;
- public:
- ...
- };
-
Don't evaluate ``end()`` every time through a loop
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
projects / oota-llvm.git / blobdiff