Remove std::string alias (for real this time)

Also use std::string_view in a few more places.

Author: edolstra

perl/lib/Nix/Store.xs

@@ -240,7 +240,7 @@ SV * convertHash(char * algo, char * s, int toBase32)
     PPCODE:
         try {
             auto h = Hash::parseAny(s, parseHashType(algo));
-            string s = h.to_string(toBase32 ? Base32 : Base16, false);
+            auto s = h.to_string(toBase32 ? Base32 : Base16, false);
             XPUSHs(sv_2mortal(newSVpv(s.c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());

src/build-remote/build-remote.cc

@@ -32,7 +32,7 @@ std::string escapeUri(std::string uri)
     return uri;
 }
 
-static string currentLoad;
+static std::string currentLoad;
 
 static AutoCloseFD openSlotLock(const Machine & m, uint64_t slot)
 {
@@ -97,7 +97,7 @@ static int main_build_remote(int argc, char * * argv)
         }
 
         std::optional<StorePath> drvPath;
-        string storeUri;
+        std::string storeUri;
 
         while (true) {
 
@@ -183,7 +183,7 @@ static int main_build_remote(int argc, char * * argv)
                     else
                     {
                         // build the hint template.
-                        string errorText =
+                        std::string errorText =
                             "Failed to find a machine for remote build!\n"
                             "derivation: %s\nrequired (system, features): (%s, %s)";
                         errorText += "\n%s available machines:";
@@ -193,7 +193,7 @@ static int main_build_remote(int argc, char * * argv)
                             errorText += "\n(%s, %s, %s, %s)";
 
                         // add the template values.
-                        string drvstr;
+                        std::string drvstr;
                         if (drvPath.has_value())
                             drvstr = drvPath->to_string();
                         else
@@ -208,7 +208,7 @@ static int main_build_remote(int argc, char * * argv)
 
                         for (auto & m : machines)
                             error
-                                % concatStringsSep<std::vector<string>>(", ", m.systemTypes)
+                                % concatStringsSep<std::vector<std::string>>(", ", m.systemTypes)
                                 % m.maxJobs
                                 % concatStringsSep<StringSet>(", ", m.supportedFeatures)
                                 % concatStringsSep<StringSet>(", ", m.mandatoryFeatures);

src/libexpr/attr-path.cc

@@ -9,7 +9,7 @@ namespace nix {
 static Strings parseAttrPath(std::string_view s)
 {
     Strings res;
-    string cur;
+    std::string cur;
     auto i = s.begin();
     while (i != s.end()) {
         if (*i == '.') {
@@ -41,7 +41,7 @@ std::vector<Symbol> parseAttrPath(EvalState & state, std::string_view s)
 }
 
 
-std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attrPath,
+std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const std::string & attrPath,
     Bindings & autoArgs, Value & vIn)
 {
     Strings tokens = parseAttrPath(attrPath);
@@ -121,7 +121,7 @@ Pos findPackageFilename(EvalState & state, Value & v, std::string what)
     std::string filename(pos, 0, colon);
     unsigned int lineno;
     try {
-        lineno = std::stoi(std::string(pos, colon + 1, string::npos));
+        lineno = std::stoi(std::string(pos, colon + 1, std::string::npos));
     } catch (std::invalid_argument & e) {
         throw ParseError("cannot parse line number '%s'", pos);
     }

src/libexpr/attr-path.hh

@@ -10,8 +10,11 @@ namespace nix {
 MakeError(AttrPathNotFound, Error);
 MakeError(NoPositionInfo, Error);
 
-std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attrPath,
-    Bindings & autoArgs, Value & vIn);
+std::pair<Value *, Pos> findAlongAttrPath(
+    EvalState & state,
+    const std::string & attrPath,
+    Bindings & autoArgs,
+    Value & vIn);
 
 /* Heuristic to find the filename and lineno or a nix value. */
 Pos findPackageFilename(EvalState & state, Value & v, std::string what);

src/libexpr/attr-set.hh

@@ -105,7 +105,7 @@ public:
         for (size_t n = 0; n < size_; n++)
             res.emplace_back(&attrs[n]);
         std::sort(res.begin(), res.end(), [](const Attr * a, const Attr * b) {
-            return (const string &) a->name < (const string &) b->name;
+            return (const std::string &) a->name < (const std::string &) b->name;
         });
         return res;
     }

src/libexpr/common-eval-args.cc

@@ -77,25 +77,25 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
     for (auto & i : autoArgs) {
         auto v = state.allocValue();
         if (i.second[0] == 'E')
-            state.mkThunk_(*v, state.parseExprFromString(string(i.second, 1), absPath(".")));
+            state.mkThunk_(*v, state.parseExprFromString(i.second.substr(1), absPath(".")));
         else
             v->mkString(((std::string_view) i.second).substr(1));
         res.insert(state.symbols.create(i.first), v);
     }
     return res.finish();
 }
 
-Path lookupFileArg(EvalState & state, string s)
+Path lookupFileArg(EvalState & state, std::string_view s)
 {
     if (isUri(s)) {
         return state.store->toRealPath(
             fetchers::downloadTarball(
                 state.store, resolveUri(s), "source", false).first.storePath);
     } else if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
-        Path p = s.substr(1, s.size() - 2);
+        Path p(s.substr(1, s.size() - 2));
         return state.findFile(p);
     } else
-        return absPath(s);
+        return absPath(std::string(s));
 }
 
 }

src/libexpr/common-eval-args.hh

@@ -22,6 +22,6 @@ private:
     std::map<std::string, std::string> autoArgs;
 };
 
-Path lookupFileArg(EvalState & state, string s);
+Path lookupFileArg(EvalState & state, std::string_view s);
 
 }

src/libexpr/eval-cache.cc

@@ -596,7 +596,7 @@ std::vector<Symbol> AttrCursor::getAttrs()
     for (auto & attr : *getValue().attrs)
         attrs.push_back(attr.name);
     std::sort(attrs.begin(), attrs.end(), [](const Symbol & a, const Symbol & b) {
-        return (const string &) a < (const string &) b;
+        return (const std::string &) a < (const std::string &) b;
     });
 
     if (root->db)