Use uncaught_exceptions() if available

C++17 deprecated uncaught_exception() and GCC 8 now issues a warning.

1 files changed, 11 insertions, 6 deletions

diff --git a/mod/diagnostics.cxx b/mod/diagnostics.cxx
index 07fd86c..601ecab 100644
--- a/mod/diagnostics.cxx
+++ b/mod/diagnostics.cxx
@@ -5,6 +5,7 @@
 #include <mod/diagnostics.hxx>
 
 using namespace std;
+using namespace butl;
 
 namespace brep
 {
@@ -12,14 +13,18 @@ namespace brep
   ~diag_record () noexcept(false)
   {
     // Don't flush the record if this destructor was called as part of
-    // the stack unwinding. Right now this means we cannot use this
-    // mechanism in destructors, which is not a big deal, except for
-    // one place: exception_guard. So for now we are going to have
-    // this ugly special check which we will be able to get rid of
-    // once C++17 uncaught_exceptions() becomes available.
+    // the stack unwinding.
+    //
+#ifdef __cpp_lib_uncaught_exceptions
+    if (!data_.empty () && uncaught_ == uncaught_exceptions ())
+#else
+    // Fallback implementation. Right now this means we cannot use this
+    // mechanism in destructors, which is not a big deal, except for one
+    // place: exception_guard. Thus the ugly special check.
     //
     if (!data_.empty () &&
-        (!uncaught_exception () /*|| exception_unwinding_dtor*/))
+        (!uncaught_exception () || exception_unwinding_dtor ()))
+#endif
     {
       data_.back ().msg = os_.str (); // Save last message.