diff --git a/distrho/DistrhoDetails.hpp b/distrho/DistrhoDetails.hpp
index 452a78ac..f72608f7 100644
--- a/distrho/DistrhoDetails.hpp
+++ b/distrho/DistrhoDetails.hpp
@@ -511,15 +511,6 @@ struct ParameterEnumerationValue {
     ParameterEnumerationValue(float v, const char* l) noexcept
         : value(v),
           label(l) {}
-
-#if __cplusplus >= 201703L
-   /**
-      Constructor using custom values, constexpr compatible variant.
-    */
-    constexpr ParameterEnumerationValue(float v, const std::string_view& l) noexcept
-        : value(v),
-          label(l) {}
-#endif
 };
 
 /**
@@ -714,29 +705,6 @@ struct Parameter {
           groupId(kPortGroupNone) {}
 #endif
 
-#if __cplusplus >= 201703L
-   /**
-      Constructor for constexpr compatible data.
-    */
-    constexpr Parameter(uint32_t h,
-                        const std::string_view& n,
-                        const std::string_view& sn,
-                        const std::string_view& sym,
-                        const std::string_view& u,
-                        const std::string_view& desc) noexcept
-        : hints(h),
-          name(n),
-          shortName(sn),
-          symbol(sym),
-          unit(u),
-          description(desc),
-          ranges(),
-          enumValues(),
-          designation(kParameterDesignationNull),
-          midiCC(0),
-          groupId(kPortGroupNone) {}
-#endif
-
    /**
       Initialize a parameter for a specific designation.
     */
@@ -762,17 +730,57 @@ struct Parameter {
             break;
         }
     }
-};
 
-#if __cplusplus >= 202001L /* TODO */
-/**
-   Bypass parameter definition in constexpr form.
- */
-static constexpr const Parameter kParameterBypass = {
-    kParameterIsAutomatable|kParameterIsBoolean|kParameterIsInteger,
-    "Bypass", "Bypass", ParameterDesignationSymbols::bypass, "", "", {}, {}, 0, kPortGroupNone,
+    Parameter& operator=(Parameter& other) noexcept
+    {
+         hints = other.hints;
+         name = other.name;
+         shortName = other.shortName;
+         symbol = other.symbol;
+         unit = other.unit;
+         description = other.description;
+         ranges = other.ranges;
+         designation = other.designation;
+         midiCC = other.midiCC;
+         groupId = other.groupId;
+
+         // enumValues needs special handling
+         enumValues.count = other.enumValues.count;
+         enumValues.restrictedMode = other.enumValues.restrictedMode;
+         enumValues.values = other.enumValues.values;
+         enumValues.deleteLater = other.enumValues.deleteLater;
+
+         // make sure to not delete data twice
+         other.enumValues.deleteLater = false;
+
+         return *this;
+    }
+
+    Parameter& operator=(const Parameter& other) noexcept
+    {
+         hints = other.hints;
+         name = other.name;
+         shortName = other.shortName;
+         symbol = other.symbol;
+         unit = other.unit;
+         description = other.description;
+         ranges = other.ranges;
+         designation = other.designation;
+         midiCC = other.midiCC;
+         groupId = other.groupId;
+
+         // make sure to not delete data twice
+         DISTRHO_SAFE_ASSERT_RETURN(other.enumValues.values == nullptr || !other.enumValues.deleteLater, *this);
+
+         // enumValues needs special handling
+         enumValues.count = other.enumValues.count;
+         enumValues.restrictedMode = other.enumValues.restrictedMode;
+         enumValues.values = other.enumValues.values;
+         enumValues.deleteLater = other.enumValues.deleteLater;
+
+         return *this;
+    }
 };
-#endif
 
 /**
    Port Group.@n
diff --git a/distrho/extra/String.hpp b/distrho/extra/String.hpp
index d61d5c43..08bd6bed 100644
--- a/distrho/extra/String.hpp
+++ b/distrho/extra/String.hpp
@@ -1,6 +1,6 @@
 /*
  * DISTRHO Plugin Framework (DPF)
- * Copyright (C) 2012-2023 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2012-2024 Filipe Coelho <falktx@falktx.com>
  *
  * Permission to use, copy, modify, and/or distribute this software for any purpose with
  * or without fee is hereby granted, provided that the above copyright notice and this
@@ -22,10 +22,6 @@
 
 #include <algorithm>
 
-#if __cplusplus >= 201703L
-# include <string_view>
-#endif
-
 START_NAMESPACE_DISTRHO
 
 // -----------------------------------------------------------------------
@@ -91,16 +87,6 @@ public:
         _dup(strBuf);
     }
 
-   #if __cplusplus >= 201703L
-    /*
-     * constexpr compatible variant.
-     */
-    explicit constexpr String(const std::string_view& strView) noexcept
-        : fBuffer(const_cast<char*>(strView.data())),
-          fBufferLen(strView.size()),
-          fBufferAlloc(false) {}
-   #endif
-
     /*
      * Integer.
      */
@@ -695,11 +681,11 @@ public:
             "abcdefghijklmnopqrstuvwxyz"
             "0123456789+/";
 
-#ifndef _MSC_VER
+       #ifndef _MSC_VER
         const std::size_t kTmpBufSize = std::min(d_nextPowerOf2(static_cast<uint32_t>(dataSize/3)), 65536U);
-#else
+       #else
         constexpr std::size_t kTmpBufSize = 65536U;
-#endif
+       #endif
 
         const uchar* bytesToEncode((const uchar*)data);