Implement string_view from the library fundamentals TS (n4023). Also works in C++11 and 03, with reduced functionality (mostly in the area of constexpr)
llvm-svn: 210659
diff --git a/libcxx/test/experimental/string.view/string.view.access/at.pass.cpp b/libcxx/test/experimental/string.view/string.view.access/at.pass.cpp
new file mode 100644
index 0000000..849a2a3
--- /dev/null
+++ b/libcxx/test/experimental/string.view/string.view.access/at.pass.cpp
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+
+// <string_view>
+
+// constexpr const _CharT& at(size_type _pos) const;
+
+#include <experimental/string_view>
+#include <cassert>
+
+template <typename CharT>
+void test ( const CharT *s, size_t len ) {
+ std::experimental::basic_string_view<CharT> sv ( s, len );
+ assert ( sv.length() == len );
+ for ( size_t i = 0; i < len; ++i ) {
+ assert ( sv.at(i) == s[i] );
+ assert ( &sv.at(i) == s + i );
+ }
+
+ try { sv.at(len); } catch ( const std::out_of_range & ) { return ; }
+ assert ( false );
+ }
+
+int main () {
+ test ( "ABCDE", 5 );
+ test ( "a", 1 );
+
+ test ( L"ABCDE", 5 );
+ test ( L"a", 1 );
+
+#if __cplusplus >= 201103L
+ test ( u"ABCDE", 5 );
+ test ( u"a", 1 );
+
+ test ( U"ABCDE", 5 );
+ test ( U"a", 1 );
+#endif
+
+#if _LIBCPP_STD_VER > 11
+ {
+ constexpr std::experimental::basic_string_view<char> sv ( "ABC", 2 );
+ static_assert ( sv.length() == 2, "" );
+ static_assert ( sv.at(0) == 'A', "" );
+ static_assert ( sv.at(1) == 'B', "" );
+ }
+#endif
+}