refactor(3p/nix): Apply clang-tidy's readability-* fixes r/788

This applies the readability fixes listed here:

https://clang.llvm.org/extra/clang-tidy/checks/list.html

1 files changed, 3 insertions, 3 deletions

diff --git a/third_party/nix/src/nix/upgrade-nix.cc b/third_party/nix/src/nix/upgrade-nix.cc
index dd11da0087..b225aac2d7 100644
--- a/third_party/nix/src/nix/upgrade-nix.cc
+++ b/third_party/nix/src/nix/upgrade-nix.cc
@@ -52,7 +52,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
   void run(ref<Store> store) override {
     evalSettings.pureEval = true;
 
-    if (profileDir == "") {
+    if (profileDir.empty()) {
       profileDir = getProfileDir(store);
     }
 
@@ -97,7 +97,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
   }
 
   /* Return the profile in which Nix is installed. */
-  Path getProfileDir(ref<Store> store) {
+  static Path getProfileDir(ref<Store> store) {
     Path where;
 
     for (auto& dir : tokenizeString<Strings>(getEnv("PATH"), ":")) {
@@ -107,7 +107,7 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
       }
     }
 
-    if (where == "") {
+    if (where.empty()) {
       throw Error(
           "couldn't figure out how Nix is installed, so I can't upgrade it");
     }