refactor(3p/nix/libexpr): Use std::string as qualified type r/797

Replaces most uses of `string` with `std::string`.

This came up because I removed the "types.hh" import from
"symbol-table.hh", which percolated through a bunch of files where
`string` was suddenly no longer defined ... *sigh*

1 files changed, 1 insertions, 1 deletions

diff --git a/third_party/nix/src/libexpr/symbol-table.cc b/third_party/nix/src/libexpr/symbol-table.cc
index 5b9fb27d59..6abaedc517 100644
--- a/third_party/nix/src/libexpr/symbol-table.cc
+++ b/third_party/nix/src/libexpr/symbol-table.cc
@@ -7,7 +7,7 @@ namespace nix {
 
 Symbol SymbolTable::Create(absl::string_view sym) {
   auto it = symbols_.emplace(sym);
-  const string* ptr = &(*it.first);
+  const std::string* ptr = &(*it.first);
   return Symbol(ptr);
 }