Fix Clang 21 compiler warning

Author: nx10

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: httpgd
 Type: Package
 Title: A 'HTTP' Server Graphics Device
-Version: 2.1.0
+Version: 2.1.1
 Authors@R: 
     c(
       person(given = "Florian", family = "Rupprecht", email = "floruppr@gmail.com", role = c("aut", "cre"), comment = c(ORCID = "0000-0002-1795-8624")),

NEWS.md

@@ -1,3 +1,7 @@
+# httpgd 2.1.1
+
+- Fix compilation failure with 'Clang 21' (vendored 'CrowCpp' CORS middleware default constructor).
+
 # httpgd 2.1.0
 
 - Update vendored 'CrowCpp' library to v1.2.1.

cran-comments.md

@@ -17,6 +17,7 @@ Relevant changes since archival:
 - Updated vendored CrowCpp library to v1.2.1 (fixes deprecated literal operator warning).
 - Updated AsioHeaders dependency to >= 1.28.2 (fixes macOS `allocator<void>` deprecation warnings).
 - Removed unused function and unused private fields that caused compiler warnings.
+- Fixed vendored CrowCpp CORS middleware default constructor for Clang 21 compatibility.
 
 ## Downstream dependencies
 There are no downstream dependencies.

src/lib/VENDOR.md

@@ -24,6 +24,10 @@
    `operator"" _method` → `operator""_method`. Clang 20 warns about this
    (`-Wdeprecated-literal-operator`); the spaced form is deprecated in C++23.
 
+5. **middlewares/cors.h:101** - Changed `CORSRules() = delete` to
+   `CORSRules() : handler_(nullptr) {}`. Clang 21 requires `CORSHandler` to be
+   default-constructible for `std::tuple` member initialization in `Crow()`.
+
 ### Patches that were needed in older versions but are now fixed upstream
 
 - **json.h** `_LIBCPP_VERSION` preprocessor guard - fixed in v1.2.1.

src/lib/crow/middlewares/cors.h

@@ -98,7 +98,7 @@ namespace crow
         CORSRules& global();
 
     private:
-        CORSRules() = delete;
+        CORSRules() : handler_(nullptr) {}
         CORSRules(CORSHandler* handler):
           handler_(handler) {}