refactor(tvix/libutil): Mark single-argument constructors explicit r/1704

This is the clang-tidy lint 'google-explicit-constructor'.

There's a whole bunch of breakage that was introduced by this, and we
had to opt out a few types of this (esp. the string formatting crap).

In some cases minor other changes have been done to keep the code
working, instead of converting between types (e.g. an explicit
comparison operator implementation for nix::Pid).

Change-Id: I12e1ca51a6bc2c882dba81a2526b9729d26988e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1832
Tested-by: BuildkiteCI
Reviewed-by: kanepyork <rikingcoding@gmail.com>
Reviewed-by: glittershark <grfn@gws.fyi>

1 files changed, 9 insertions, 7 deletions

diff --git a/third_party/nix/src/libutil/json.hh b/third_party/nix/src/libutil/json.hh
index a3843a8a8a..14d61d8a57 100644
--- a/third_party/nix/src/libutil/json.hh
+++ b/third_party/nix/src/libutil/json.hh
@@ -29,7 +29,7 @@ class JSONWriter {
 
   JSONWriter(std::ostream& str, bool indent);
 
-  JSONWriter(JSONState* state);
+  explicit JSONWriter(JSONState* state);
 
   ~JSONWriter();
 
@@ -50,10 +50,11 @@ class JSONList : JSONWriter {
 
   void open();
 
-  JSONList(JSONState* state) : JSONWriter(state) { open(); }
+  explicit JSONList(JSONState* state) : JSONWriter(state) { open(); }
 
  public:
-  JSONList(std::ostream& str, bool indent = false) : JSONWriter(str, indent) {
+  explicit JSONList(std::ostream& str, bool indent = false)
+      : JSONWriter(str, indent) {
     open();
   }
 
@@ -80,12 +81,13 @@ class JSONObject : JSONWriter {
 
   void open();
 
-  JSONObject(JSONState* state) : JSONWriter(state) { open(); }
+  explicit JSONObject(JSONState* state) : JSONWriter(state) { open(); }
 
   void attr(const std::string& s);
 
  public:
-  JSONObject(std::ostream& str, bool indent = false) : JSONWriter(str, indent) {
+  explicit JSONObject(std::ostream& str, bool indent = false)
+      : JSONWriter(str, indent) {
     open();
   }
 
@@ -114,7 +116,7 @@ class JSONPlaceholder : JSONWriter {
   friend class JSONList;
   friend class JSONObject;
 
-  JSONPlaceholder(JSONState* state) : JSONWriter(state) {}
+  explicit JSONPlaceholder(JSONState* state) : JSONWriter(state) {}
 
   void assertValid() {
     assertActive();
@@ -122,7 +124,7 @@ class JSONPlaceholder : JSONWriter {
   }
 
  public:
-  JSONPlaceholder(std::ostream& str, bool indent = false)
+  explicit JSONPlaceholder(std::ostream& str, bool indent = false)
       : JSONWriter(str, indent) {}
 
   ~JSONPlaceholder() { assert(!first || std::uncaught_exception()); }