Fix gcc warning -Wmissing-field-initializers

The approach that was taken here was to add default values to the type
definitions rather than specify them whenever they are missing.

Now the only remaining warning is '-Wunused-parameter' which @jade said
is usually counterproductive and that we can just disable it:
https://git.lix.systems/lix-project/lix/issues/456#issuecomment-6617

So this change adds the flags '-Wall', '-Wextra' and
'-Wno-unused-parameter', so that all warnings are enabled except for
'-Wunused-parameter'.

Change-Id: Ic223a964d67ab429e8da804c0721ba5e25d53012

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstore/nar-accessor.cc b/src/libstore/nar-accessor.cc
index 7600de6e7..f228004a9 100644
--- a/src/libstore/nar-accessor.cc
+++ b/src/libstore/nar-accessor.cc
@@ -20,10 +20,10 @@ struct NarMember
        file in the NAR. */
     uint64_t start = 0, size = 0;
 
-    std::string target;
+    std::string target = {};
 
     /* If this is a directory, all the children of the directory. */
-    std::map<std::string, NarMember> children;
+    std::map<std::string, NarMember> children = {};
 };
 
 struct NarAccessor : public FSAccessor