Mark 'front()' and 'back()' as noexcept for array/deque/string/string_view. These are just rebranded 'operator[]', and should be noexcept like it is.

llvm-svn: 356435
diff --git a/libcxx/test/std/strings/basic.string/string.access/back.pass.cpp b/libcxx/test/std/strings/basic.string/string.access/back.pass.cpp
index 3831da0..dd2a59a 100644
--- a/libcxx/test/std/strings/basic.string/string.access/back.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.access/back.pass.cpp
@@ -25,6 +25,10 @@
 test(S s)
 {
     const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s.back()), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs.back()), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s.back());
+    LIBCPP_ASSERT_NOEXCEPT(   cs.back());
     assert(&cs.back() == &cs[cs.size()-1]);
     assert(&s.back() == &s[cs.size()-1]);
     s.back() = typename S::value_type('z');
diff --git a/libcxx/test/std/strings/basic.string/string.access/front.pass.cpp b/libcxx/test/std/strings/basic.string/string.access/front.pass.cpp
index d51a12f..b666c9c 100644
--- a/libcxx/test/std/strings/basic.string/string.access/front.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.access/front.pass.cpp
@@ -25,6 +25,10 @@
 test(S s)
 {
     const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s.front()), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs.front()), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s.front());
+    LIBCPP_ASSERT_NOEXCEPT(   cs.front());
     assert(&cs.front() == &cs[0]);
     assert(&s.front() == &s[0]);
     s.front() = typename S::value_type('z');
diff --git a/libcxx/test/std/strings/basic.string/string.access/index.pass.cpp b/libcxx/test/std/strings/basic.string/string.access/index.pass.cpp
index 3a1224c..ec02fa4 100644
--- a/libcxx/test/std/strings/basic.string/string.access/index.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.access/index.pass.cpp
@@ -26,6 +26,10 @@
     typedef std::string S;
     S s("0123456789");
     const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s[0]);
+    LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
     for (S::size_type i = 0; i < cs.size(); ++i)
     {
         assert(s[i] == static_cast<char>('0' + i));
@@ -40,6 +44,10 @@
     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
     S s("0123456789");
     const S& cs = s;
+    ASSERT_SAME_TYPE(decltype( s[0]), typename S::reference);
+    ASSERT_SAME_TYPE(decltype(cs[0]), typename S::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(    s[0]);
+    LIBCPP_ASSERT_NOEXCEPT(   cs[0]);
     for (S::size_type i = 0; i < cs.size(); ++i)
     {
         assert(s[i] == static_cast<char>('0' + i));
diff --git a/libcxx/test/std/strings/string.view/string.view.access/back.pass.cpp b/libcxx/test/std/strings/string.view/string.view.access/back.pass.cpp
index 4505f1c..76487b1 100644
--- a/libcxx/test/std/strings/string.view/string.view.access/back.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.access/back.pass.cpp
@@ -18,7 +18,10 @@
 
 template <typename CharT>
 bool test ( const CharT *s, size_t len ) {
-    std::basic_string_view<CharT> sv ( s, len );
+    typedef std::basic_string_view<CharT> SV;
+    SV sv ( s, len );
+    ASSERT_SAME_TYPE(decltype(sv.back()), typename SV::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(   sv.back());
     assert ( sv.length() == len );
     assert ( sv.back() == s[len-1] );
     return &sv.back() == s + len - 1;
diff --git a/libcxx/test/std/strings/string.view/string.view.access/front.pass.cpp b/libcxx/test/std/strings/string.view/string.view.access/front.pass.cpp
index 554ed1b..eb71389 100644
--- a/libcxx/test/std/strings/string.view/string.view.access/front.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.access/front.pass.cpp
@@ -18,7 +18,10 @@
 
 template <typename CharT>
 bool test ( const CharT *s, size_t len ) {
-    std::basic_string_view<CharT> sv ( s, len );
+    typedef std::basic_string_view<CharT> SV;
+    SV sv ( s, len );
+    ASSERT_SAME_TYPE(decltype(sv.front()), typename SV::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(   sv.front());
     assert ( sv.length() == len );
     assert ( sv.front() == s[0] );
     return &sv.front() == s;
diff --git a/libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp b/libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp
index 33992de..05b704c 100644
--- a/libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.access/index.pass.cpp
@@ -18,7 +18,10 @@
 
 template <typename CharT>
 void test ( const CharT *s, size_t len ) {
-    std::basic_string_view<CharT> sv ( s, len );
+    typedef std::basic_string_view<CharT> SV;
+    SV sv ( s, len );
+    ASSERT_SAME_TYPE(decltype(sv[0]), typename SV::const_reference);
+    LIBCPP_ASSERT_NOEXCEPT(   sv[0]);
     assert ( sv.length() == len );
     for ( size_t i = 0; i < len; ++i ) {
         assert ( sv[i] == s[i] );