Make `--read-only` a separate mixin

It is independent of SourceExprCommand, which is about parsing
installables, except for the fact that parsing installables is one of
the many things influenced by read-only mode.

1 files changed, 7 insertions, 3 deletions

diff --git a/src/libcmd/command.hh b/src/libcmd/command.hh
index 1516daa00..b6d554aab 100644
--- a/src/libcmd/command.hh
+++ b/src/libcmd/command.hh
@@ -94,9 +94,8 @@ struct SourceExprCommand : virtual Args, MixFlakeOptions
 {
     std::optional<Path> file;
     std::optional<std::string> expr;
-    bool readOnlyMode = false;
 
-    SourceExprCommand(bool supportReadOnlyMode = false);
+    SourceExprCommand();
 
     std::vector<std::shared_ptr<Installable>> parseInstallables(
         ref<Store> store, std::vector<std::string> ss);
@@ -111,6 +110,11 @@ struct SourceExprCommand : virtual Args, MixFlakeOptions
     void completeInstallable(std::string_view prefix);
 };
 
+struct MixReadOnlyOption : virtual Args
+{
+    MixReadOnlyOption();
+};
+
 /* A command that operates on a list of "installables", which can be
    store paths, attribute paths, Nix expressions, etc. */
 struct InstallablesCommand : virtual Args, SourceExprCommand
@@ -136,7 +140,7 @@ struct InstallableCommand : virtual Args, SourceExprCommand
 {
     std::shared_ptr<Installable> installable;
 
-    InstallableCommand(bool supportReadOnlyMode = false);
+    InstallableCommand();
 
     void prepare() override;