Features: Add cxx_raw_string_literals.

Help/variable/CMAKE_CXX_KNOWN_FEATURES.rst

@@ -87,6 +87,11 @@ The features known to this version of CMake are:
 
   .. _N2930: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2930.html
 
+``cxx_raw_string_literals``
+  Raw string literals, as defined in N2442_.
+
+  .. _N2442: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm
+
 ``cxx_static_assert``
   Static assert, as defined in N1720_.
 

Modules/Compiler/GNU-CXX-FeatureTests.cmake

@@ -25,6 +25,7 @@ set(_cmake_feature_test_cxx_range_for "${GNU46_CXX11}")
 set(GNU45_CXX11 "${_oldestSupported} && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_explicit_conversions "${GNU45_CXX11}")
 set(_cmake_feature_test_cxx_lambdas "${GNU45_CXX11}")
+set(_cmake_feature_test_cxx_raw_string_literals "${GNU45_CXX11}")
 # TODO: Should be supported by GNU 4.4
 set(GNU44_CXX11 "${_oldestSupported} && __cplusplus >= 201103L")
 set(_cmake_feature_test_cxx_auto_type "${GNU44_CXX11}")

Source/cmMakefile.cxx

@@ -57,6 +57,7 @@
   F(cxx_nullptr) \
   F(cxx_override) \
   F(cxx_range_for) \
+  F(cxx_raw_string_literals) \
   F(cxx_static_assert) \
   F(cxx_strong_enums) \
   F(cxx_trailing_return_types) \

Tests/CompileFeatures/cxx_raw_string_literals.cpp

@@ -0,0 +1,7 @@
+
+void someFunc()
+{
+const char p[] = R"(a\
+b
+c)";
+}