refactor(3p/nix): Apply clang-tidy's modernize-* fixes r/787

This applies the modernization fixes listed here:

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

The 'modernize-use-trailing-return-type' fix was excluded due to my
personal preference (more specifically, I think the 'auto' keyword is
misleading in that position).

1 files changed, 2 insertions, 3 deletions

diff --git a/third_party/nix/src/nix/search.cc b/third_party/nix/src/nix/search.cc
index 5978d197fe..78a1f21bc1 100644
--- a/third_party/nix/src/nix/search.cc
+++ b/third_party/nix/src/nix/search.cc
@@ -76,15 +76,14 @@ struct CmdSearch : SourceExprCommand, MixJSON {
     // Use "^" here instead of ".*" due to differences in resulting highlighting
     // (see #1893 -- libc++ claims empty search string is not in POSIX grammar)
     if (res.empty()) {
-      res.push_back("^");
+      res.emplace_back("^");
     }
 
     std::vector<std::regex> regexes;
     regexes.reserve(res.size());
 
     for (auto& re : res) {
-      regexes.push_back(
-          std::regex(re, std::regex::extended | std::regex::icase));
+      regexes.emplace_back(re, std::regex::extended | std::regex::icase);
     }
 
     auto state = getEvalState();