style(3p/nix): Remove 'using std::*' from types.hh r/840

It is considered bad form to use things from includes in headers, as
these directives propagate to everywhere else and can make it
confusing.

types.hh (which is includes almost literally everywhere) had some of
these directives, which this commit removes.

1 files changed, 1 insertions, 1 deletions

diff --git a/third_party/nix/src/nix/hash.cc b/third_party/nix/src/nix/hash.cc
index 74ff45d0d8..c500dc4f3c 100644
--- a/third_party/nix/src/nix/hash.cc
+++ b/third_party/nix/src/nix/hash.cc
@@ -106,7 +106,7 @@ static int compatNixHash(int argc, char** argv) {
                  } else if (*arg == "--truncate") {
                    truncate = true;
                  } else if (*arg == "--type") {
-                   string s = getArg(*arg, arg, end);
+                   std::string s = getArg(*arg, arg, end);
                    ht = parseHashType(s);
                    if (ht == htUnknown) {
                      throw UsageError(format("unknown hash type '%1%'") % s);