Value: extract Value::StringWithContext

src/libexpr/value.hh

@@ -158,18 +158,13 @@ public:
     inline bool isPrimOp() const { return internalType == tPrimOp; };
     inline bool isPrimOpApp() const { return internalType == tPrimOpApp; };
 
-    union
-    {
-        NixInt integer;
-        bool boolean;
-
     /**
      * Strings in the evaluator carry a so-called `context` which
      * is a list of strings representing store paths.  This is to
      * allow users to write things like
-
+     *
      *   "--with-freetype2-library=" + freetype + "/lib"
-
+     *
      * where `freetype` is a derivation (or a source to be copied
      * to the store).  If we just concatenated the strings without
      * keeping track of the referenced store paths, then if the
@@ -185,10 +180,17 @@ public:
 
      * For canonicity, the store paths should be in sorted order.
      */
-        struct {
+    struct StringWithContext {
         const char * c_str;
         const char * * context; // must be in sorted order
-        } string;
+    };
+
+    union
+    {
+        NixInt integer;
+        bool boolean;
+
+        StringWithContext string;
 
         struct {
             InputAccessor * accessor;