From 04c5b99f38aef9a5c9627c35659891aecd8ab41e Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Fri, 4 Apr 2014 10:56:09 +0200
Subject: [PATCH] Features: Add cxx_user_literals.

---
 Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst  | 5 +++++
 Modules/Compiler/GNU-CXX-FeatureTests.cmake | 1 +
 Source/cmMakefile.cxx                       | 1 +
 Tests/CompileFeatures/cxx_user_literals.cpp | 7 +++++++
 4 files changed, 14 insertions(+)
 create mode 100644 Tests/CompileFeatures/cxx_user_literals.cpp

diff --git a/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst b/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst
index fbc45c2e6..1ea3b681b 100644
--- a/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst
+++ b/Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst
@@ -122,6 +122,11 @@ The features known to this version of CMake are:
 
   .. _N2541: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2541.htm
 
+``cxx_user_literals``
+  User-defined literals, as defined in N2765_.
+
+  .. _N2765: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2765.pdf
+
 ``cxx_variadic_templates``
   Variadic templates, as defined in N2242_.
 
diff --git a/Modules/Compiler/GNU-CXX-FeatureTests.cmake b/Modules/Compiler/GNU-CXX-FeatureTests.cmake
index 5f8d95231..12d2adc26 100644
--- a/Modules/Compiler/GNU-CXX-FeatureTests.cmake
+++ b/Modules/Compiler/GNU-CXX-FeatureTests.cmake
@@ -15,6 +15,7 @@ set(_cmake_feature_test_cxx_final "${GNU47_CXX11}")
 set(_cmake_feature_test_cxx_noexcept "${GNU47_CXX11}")
 set(_cmake_feature_test_cxx_nonstatic_member_init "${GNU47_CXX11}")
 set(_cmake_feature_test_cxx_override "${GNU47_CXX11}")
+set(_cmake_feature_test_cxx_user_literals "${GNU47_CXX11}")
 # NOTE: C++11 was ratified in September 2011. GNU 4.7 is the first minor
 # release following that (March 2012), and the first minor release to
 # support -std=c++11. Prior to that, support for C++11 features is technically
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index fc89d8e7c..bcd192d76 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -64,6 +64,7 @@
   F(cxx_static_assert) \
   F(cxx_strong_enums) \
   F(cxx_trailing_return_types) \
+  F(cxx_user_literals) \
   F(cxx_variadic_templates)
 
 class cmMakefile::Internals
diff --git a/Tests/CompileFeatures/cxx_user_literals.cpp b/Tests/CompileFeatures/cxx_user_literals.cpp
new file mode 100644
index 000000000..9e5a5889e
--- /dev/null
+++ b/Tests/CompileFeatures/cxx_user_literals.cpp
@@ -0,0 +1,7 @@
+
+long double operator "" _meters(long double);
+
+void someFunc()
+{
+  long double i = 1.2_meters;
+}