Use Rust Filename comparisons for C++ Filename operators

To prevent inconsistencies between implementations. This means allocating new boxed Filenames for each comparison, but an extra string copy is avoided by making the C++ operators friends of the C++ class (which is ABI-safe).

cpp/Cargo.toml

@@ -9,7 +9,6 @@ cxx = { version = "1.0", features = ["c++17"] }
 delegate = "0.13.2"
 libloot = { path = ".." }
 libloot-ffi-errors = { path = "../ffi-errors" }
-unicase = "2.8.1"
 
 [build-dependencies]
 cxx-build = "1.0"

cpp/include/loot/metadata/filename.h

@@ -54,6 +54,10 @@ public:
 
 private:
   std::string filename_;
+
+  LOOT_API friend bool operator==(const Filename& lhs, const Filename& rhs);
+
+  LOOT_API friend bool operator<(const Filename& lhs, const Filename& rhs);
 };
 
 /**

cpp/src/api/metadata/filename.cpp

@@ -35,7 +35,8 @@ Filename::Filename(std::string_view filename) : filename_(filename) {}
 Filename::operator std::string() const { return filename_; }
 
 bool operator==(const Filename& lhs, const Filename& rhs) {
-  return loot::rust::compare_filenames(std::string(lhs), std::string(rhs)) == 0;
+  return loot::rust::new_filename(lhs.filename_)
+      ->eq(*loot::rust::new_filename(rhs.filename_));
 }
 
 bool operator!=(const Filename& lhs, const Filename& rhs) {
@@ -43,7 +44,8 @@ bool operator!=(const Filename& lhs, const Filename& rhs) {
 }
 
 bool operator<(const Filename& lhs, const Filename& rhs) {
-  return loot::rust::compare_filenames(std::string(lhs), std::string(rhs)) < 0;
+  return loot::rust::new_filename(lhs.filename_)
+             ->lt(*loot::rust::new_filename(rhs.filename_));
 }
 
 bool operator>(const Filename& lhs, const Filename& rhs) { return rhs < lhs; }

cpp/src/lib.rs

@@ -119,7 +119,6 @@ use std::{
     ffi::{CString, c_char, c_uchar, c_uint, c_void},
     sync::{Mutex, atomic::AtomicPtr},
 };
-use unicase::UniCase;
 
 use libloot::set_logging_callback;
 pub use libloot::{is_compatible, libloot_revision, libloot_version};
@@ -181,14 +180,6 @@ pub type OptionalPluginMetadata = Optional<PluginMetadata>;
 
 pub type OptionalCrc = Optional<u32>;
 
-fn compare_filenames(lhs: &str, rhs: &str) -> i8 {
-    match UniCase::new(lhs).cmp(&UniCase::new(rhs)) {
-        std::cmp::Ordering::Less => -1,
-        std::cmp::Ordering::Equal => 0,
-        std::cmp::Ordering::Greater => 1,
-    }
-}
-
 fn set_log_level(level: ffi::LogLevel) -> Result<(), VerboseError> {
     libloot::set_log_level(level.try_into()?);
     Ok(())
@@ -295,8 +286,6 @@ mod ffi {
             contents: &[MessageContent],
             language: &str,
         ) -> OptionalMessageContentRef;
-
-        fn compare_filenames(lhs: &str, rhs: &str) -> i8;
     }
 
     extern "Rust" {
@@ -633,6 +622,18 @@ mod ffi {
         pub fn as_str(&self) -> &str;
 
         pub fn boxed_clone(&self) -> Box<Filename>;
+
+        pub fn eq(&self, other: &Filename) -> bool;
+
+        pub fn ne(&self, other: &Filename) -> bool;
+
+        pub fn lt(&self, other: &Filename) -> bool;
+
+        pub fn le(&self, other: &Filename) -> bool;
+
+        pub fn gt(&self, other: &Filename) -> bool;
+
+        pub fn ge(&self, other: &Filename) -> bool;
     }
 
     extern "Rust" {

cpp/src/metadata.rs

@@ -446,7 +446,7 @@ impl From<Box<File>> for libloot::metadata::File {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq, PartialOrd)]
 #[repr(transparent)]
 pub struct Filename(libloot::metadata::Filename);