Merge branch 'master' into dev/neilmac/spec

README.md

@@ -40,7 +40,7 @@ of your GSL source.
 
 These steps assume the source code of this repository has been cloned into a directory named `c:\GSL`.
 
-1. Create a directory to contain the build outputs for a particular architecture (we name it c:\GSL\vs14-x86 in this example).
+1. Create a directory to contain the build outputs for a particular architecture (we name it c:\GSL\build-x86 in this example).
 
         cd GSL
         md build-x86

include/gsl_util.h

@@ -129,6 +129,10 @@ template <class Cont>
 constexpr typename Cont::value_type& at(Cont& cont, size_t index)
 { Expects(index < cont.size()); return cont[index]; }
 
+template <class T>
+constexpr const T& at(std::initializer_list<T> cont, size_t index)
+{ Expects(index < cont.size()); return *(cont.begin() + index); }
+
 } // namespace gsl
 
 

tests/at_tests.cpp

@@ -17,6 +17,7 @@
 #include <UnitTest++/UnitTest++.h> 
 #include <gsl.h>
 #include <vector>
+#include <initializer_list>
 
 using namespace std;
 using namespace gsl;
@@ -52,6 +53,16 @@ SUITE(at_tests)
 
         CHECK_THROW(at(a, 4), fail_fast);
     }
+
+    TEST(InitializerList)
+    {
+        std::initializer_list<int> a = { 1, 2, 3, 4 };
+
+        for (int i = 0; i < 4; ++i)
+            CHECK(at(a, i) == i+1);
+
+        CHECK_THROW(at(a, 4), fail_fast);
+    }
 }
 
 int main(int, const char *[])