This should improve string performance in ondemand by making the string processing runtime dispatched.

src/implementation.cpp

@@ -72,6 +72,9 @@ public:
   simdjson_warn_unused bool validate_utf8(const char * buf, size_t len) const noexcept final override {
     return set_best()->validate_utf8(buf, len);
   }
+  simdjson_warn_unused uint8_t *parse_string(const uint8_t *src, uint8_t *dst) const noexcept final override {
+    return set_best()->parse_string(src, dst);
+  }
   simdjson_really_inline detect_best_supported_implementation_on_first_use() noexcept : implementation("best_supported_detector", "Detects the best supported implementation and sets it", 0) {}
 private:
   const implementation *set_best() const noexcept;
@@ -124,6 +127,9 @@ public:
     // what are the chances that the programmer has a fallback? Given that *we* provide the
     // fallback, it implies that the programmer would need a fallback for our fallback.
   }
+  simdjson_warn_unused uint8_t *parse_string(const uint8_t *, uint8_t *) const noexcept final override {
+    return nullptr;
+  }
   unsupported_implementation() : implementation("unsupported", "Unsupported CPU (no detected SIMD instructions)", 0) {}
 };
 
@@ -188,7 +194,9 @@ simdjson_warn_unused error_code minify(const char *buf, size_t len, char *dst, s
 simdjson_warn_unused bool validate_utf8(const char *buf, size_t len) noexcept {
   return get_active_implementation()->validate_utf8(buf, len);
 }
-
+simdjson_warn_unused uint8_t *parse_string(const uint8_t *src, uint8_t *dst) noexcept {
+  return get_active_implementation()->parse_string(src, dst);
+}
 const implementation * builtin_implementation() {
   static const implementation * builtin_impl = get_available_implementations()[SIMDJSON_STRINGIFY(SIMDJSON_BUILTIN_IMPLEMENTATION)];
   assert(builtin_impl);