[refactor] Combine the ToString and ToPrivateString implementations

Author: sipa

src/script/descriptor.cpp

@@ -251,21 +251,25 @@ class DescriptorImpl : public Descriptor
         return false;
     }
 
-    bool ToPrivateString(const SigningProvider& arg, std::string& out) const final
+    bool ToStringHelper(const SigningProvider* arg, std::string& out, bool priv) const
     {
         std::string extra = ToStringExtra();
         size_t pos = extra.size() > 0 ? 1 : 0;
         std::string ret = m_name + "(" + extra;
         for (const auto& pubkey : m_pubkey_args) {
             if (pos++) ret += ",";
             std::string tmp;
-            if (!pubkey->ToPrivateString(arg, tmp)) return false;
+            if (priv) {
+                if (!pubkey->ToPrivateString(*arg, tmp)) return false;
+            } else {
+                tmp = pubkey->ToString();
+            }
             ret += std::move(tmp);
         }
         if (m_script_arg) {
             if (pos++) ret += ",";
             std::string tmp;
-            if (!m_script_arg->ToPrivateString(arg, tmp)) return false;
+            if (!m_script_arg->ToStringHelper(arg, tmp, priv)) return false;
             ret += std::move(tmp);
         }
         out = std::move(ret) + ")";
@@ -274,20 +278,13 @@ class DescriptorImpl : public Descriptor
 
     std::string ToString() const final
     {
-        std::string extra = ToStringExtra();
-        size_t pos = extra.size() > 0 ? 1 : 0;
-        std::string ret = m_name + "(" + extra;
-        for (const auto& pubkey : m_pubkey_args) {
-            if (pos++) ret += ",";
-            ret += pubkey->ToString();
-        }
-        if (m_script_arg) {
-            if (pos++) ret += ",";
-            ret += m_script_arg->ToString();
-        }
-        return std::move(ret) + ")";
+        std::string ret;
+        ToStringHelper(nullptr, ret, false);
+        return ret;
     }
 
+    bool ToPrivateString(const SigningProvider& arg, std::string& out) const override final { return ToStringHelper(&arg, out, true); }
+
     bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const final
     {
         std::vector<std::pair<CPubKey, KeyOriginInfo>> entries;