Recognize .hpp/.hxx/.h++ as C++ headers

crates/languages/src/lib.rs

@@ -152,7 +152,7 @@ pub fn language_by_filename(path: &Path) -> Option<Arc<Language>> {
         "tsx" => language_by_name("tsx"),
         "ts" | "cts" | "mts" => language_by_name("typescript"),
         "java" | "groovy" | "gvy" | "gy" | "gsh" => language_by_name("java"),
-        "cpp" | "cxx" | "cc" | "h" | "hh" => language_by_name("cpp"),
+        "cpp" | "cxx" | "cc" | "h" | "hh" | "hpp" | "hxx" | "h++" => language_by_name("cpp"),
         "sh" | "zsh" | "bash" => language_by_name("shell"),
         "cs" => language_by_name("csharp"),
         "html" => language_by_name("html"),

crates/languages/src/lib_tests.rs

@@ -1,4 +1,6 @@
-use crate::{load_language, SUPPORTED_LANGUAGES};
+use std::path::Path;
+
+use crate::{language_by_filename, load_language, SUPPORTED_LANGUAGES};
 
 /// Validate that every supported language can be loaded successfully.
 /// This catches invalid node types, syntax errors, and other issues in .scm query files
@@ -20,3 +22,15 @@ fn all_supported_languages_load_successfully() {
             .join("\n")
     );
 }
+
+/// Modern C++ codebases (Boost, Qt, etc.) use `.hpp` (and less often
+/// `.hxx` / `.h++`) for headers to distinguish them from plain C.
+/// Make sure each variant resolves to the C++ language.
+#[test]
+fn cpp_header_extensions_resolve_to_cpp() {
+    for name in ["foo.hpp", "foo.hxx", "foo.h++"] {
+        let language = language_by_filename(Path::new(name))
+            .unwrap_or_else(|| panic!("`{name}` should resolve to a language"));
+        assert_eq!(language.display_name, "C++", "{name} should map to C++");
+    }
+}