Merging r181342:

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r181342 | rsmith | 2013-05-07 12:32:56 -0700 (Tue, 07 May 2013) | 4 lines

C++1y: Update __cplusplus to temporary value 201305L to allow detection of provisional C++1y support.
Add __has_feature and __has_extension checks for C++1y features (based on the provisional names from
the C++ features study group), and update documentation to match.

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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_33@182340 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 92 insertions, 0 deletions

diff --git a/docs/LanguageExtensions.rst b/docs/LanguageExtensions.rst
index dbb67f908d..324feafa98 100644
--- a/docs/LanguageExtensions.rst
+++ b/docs/LanguageExtensions.rst
@@ -779,6 +779,98 @@ Use ``__has_feature(cxx_variadic_templates)`` or
 ``__has_extension(cxx_variadic_templates)`` to determine if support for
 variadic templates is enabled.
 
+C++1y
+-----
+
+The features listed below are part of the committee draft for the C++1y
+standard.  As a result, all these features are enabled with the ``-std=c++1y``
+or ``-std=gnu++1y`` option when compiling C++ code.
+
+C++1y binary literals
+^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_binary_literals)`` or
+``__has_extension(cxx_binary_literals)`` to determine whether
+binary literals (for instance, ``0b10010``) are recognized. Clang supports this
+feature as an extension in all language modes.
+
+C++1y contextual conversions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_contextual_conversions)`` or
+``__has_extension(cxx_contextual_conversions)`` to determine if the C++1y rules
+are used when performing an implicit conversion for an array bound in a
+*new-expression*, the operand of a *delete-expression*, an integral constant
+expression, or a condition in a ``switch`` statement. Clang does not yet
+support this feature.
+
+C++1y decltype(auto)
+^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_decltype_auto)`` or
+``__has_extension(cxx_decltype_auto)`` to determine if support
+for the ``decltype(auto)`` placeholder type is enabled.
+
+C++1y default initializers for aggregates
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_aggregate_nsdmi)`` or
+``__has_extension(cxx_aggregate_nsdmi)`` to determine if support
+for default initializers in aggregate members is enabled.
+
+C++1y generalized lambda capture
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_generalized_capture)`` or
+``__has_extension(cxx_generalized_capture`` to determine if support for
+generalized lambda captures is enabled
+(for instance, ``[n(0)] { return ++n; }``).
+Clang does not yet support this feature.
+
+C++1y generic lambdas
+^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_generic_lambda)`` or
+``__has_extension(cxx_generic_lambda)`` to determine if support for generic
+(polymorphic) lambdas is enabled
+(for instance, ``[] (auto x) { return x + 1; }``).
+Clang does not yet support this feature.
+
+C++1y relaxed constexpr
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_relaxed_constexpr)`` or
+``__has_extension(cxx_relaxed_constexpr)`` to determine if variable
+declarations, local variable modification, and control flow constructs
+are permitted in ``constexpr`` functions.
+Clang's implementation of this feature is incomplete.
+
+C++1y return type deduction
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_return_type_deduction)`` or
+``__has_extension(cxx_return_type_deduction)`` to determine if support
+for return type deduction for functions (using ``auto`` as a return type)
+is enabled.
+Clang's implementation of this feature is incomplete.
+
+C++1y runtime-sized arrays
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_runtime_array)`` or
+``__has_extension(cxx_runtime_array)`` to determine if support
+for arrays of runtime bound (a restricted form of variable-length arrays)
+is enabled.
+Clang's implementation of this feature is incomplete.
+
+C++1y variable templates
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Use ``__has_feature(cxx_variable_templates)`` or
+``__has_extension(cxx_variable_templates)`` to determine if support for
+templated variable declarations is enabled.
+Clang does not yet support this feature.
+
 C11
 ---