util: variant: add static assert
The two variant utilities both have an 'Unused' template parameter pack
which is expected to be empty. Add static assert to confirm the
parameter pack is indeed always empty. (Generally the non-empty
parameter pack should match with a specialization.)
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iae4523142df563d208e20ab81dd47266b3f7dd27
diff --git a/include/sdbusplus/utility/dedup_variant.hpp b/include/sdbusplus/utility/dedup_variant.hpp
index bfffd20..786f7ef 100644
--- a/include/sdbusplus/utility/dedup_variant.hpp
+++ b/include/sdbusplus/utility/dedup_variant.hpp
@@ -25,6 +25,7 @@
struct dedup_variant
{
using type = T;
+ static_assert(sizeof...(Unused) == 0);
};
/** Find the deduplicated variant type.
diff --git a/include/sdbusplus/utility/merge_variants.hpp b/include/sdbusplus/utility/merge_variants.hpp
index 89c5571..7079682 100644
--- a/include/sdbusplus/utility/merge_variants.hpp
+++ b/include/sdbusplus/utility/merge_variants.hpp
@@ -26,6 +26,7 @@
struct merge_variants
{
using type = T;
+ static_assert(sizeof...(Unused) == 0);
};
/** Compute the merged variant type.