Fix initialization in test (#1140)

* Suppress unsafe-buffer-usage

include/gsl/span

@@ -63,6 +63,12 @@
 #pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
 
+// Turn off clang unsafe buffer warnings as all accessed are guarded by runtime checks
+#if defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunsafe-buffer-usage"
+#endif // defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+
 namespace gsl
 {
 
@@ -846,4 +852,8 @@ as_writable_bytes(span<ElementType, Extent> s) noexcept
 #pragma GCC diagnostic pop
 #endif // __GNUC__ > 6
 
+#if defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+#pragma clang diagnostic pop
+#endif
+
 #endif // GSL_SPAN_H

include/gsl/util

@@ -40,6 +40,12 @@
 
 #endif // _MSC_VER
 
+// Turn off clang unsafe buffer warnings as all accessed are guarded by runtime checks
+#if defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunsafe-buffer-usage"
+#endif // defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+
 #if defined(__cplusplus) && (__cplusplus >= 201703L)
 #define GSL_NODISCARD [[nodiscard]]
 #else
@@ -154,4 +160,8 @@ constexpr auto at(std::span<T, extent> sp, const index i) -> decltype(sp[sp.size
 
 #endif // _MSC_VER
 
+#if defined(__clang__) && __has_warning("-Wunsafe-buffer-usage")
+#pragma clang diagnostic pop
+#endif
+
 #endif // GSL_UTIL_H