refactor(3p/nix): Make all single-argument constructors explicit r/778

Implicit constructors can be confusing, especially in a codebase that
is already as unintentionally obfuscated as this one.

https://google.github.io/styleguide/cppguide.html#Explicit_Constructors

1 files changed, 1 insertions, 1 deletions

diff --git a/third_party/nix/src/libstore/nar-accessor.cc b/third_party/nix/src/libstore/nar-accessor.cc
index 8be22ada2e36..ffbf7c1a89d5 100644
--- a/third_party/nix/src/libstore/nar-accessor.cc
+++ b/third_party/nix/src/libstore/nar-accessor.cc
@@ -93,7 +93,7 @@ struct NarAccessor : public FSAccessor {
     }
   };
 
-  NarAccessor(ref<const std::string> nar) : nar(nar) {
+  explicit NarAccessor(ref<const std::string> nar) : nar(nar) {
     NarIndexer indexer(*this, *nar);
     parseDump(indexer, indexer);
   }