Change APIs to make them more future proof.

Author: khuey

examples/cppfilt.rs

@@ -102,10 +102,13 @@ fn main() {
     let stderr = io::stderr();
     let mut stderr = stderr.lock();
 
-    let options = DemangleOptions {
-        no_params: matches.is_present("noparams"),
-        no_return_type: matches.is_present("noreturntype"),
-    };
+    let mut options = DemangleOptions::new();
+    if matches.is_present("noparams") {
+        options = options.no_params();
+    }
+    if matches.is_present("noreturntype") {
+        options = options.no_return_type();
+    }
 
     let demangle_result = if let Some(names) = matches.values_of("mangled_names") {
         let mut input = Cursor::new(names.fold(String::new(), |mut accumulated, name| {

src/lib.rs

@@ -86,10 +86,27 @@ use std::fmt;
 /// Options to control the demangling process.
 #[derive(Clone, Copy, Debug, Default)]
 pub struct DemangleOptions {
+    no_params: bool,
+    no_return_type: bool,
+}
+
+impl DemangleOptions {
+    /// Construct a new `DemangleOptions` with the default values.
+    pub fn new() -> Self {
+        Default::default()
+    }
+
     /// Do not display function arguments.
-    pub no_params: bool,
+    pub fn no_params(mut self) -> Self {
+        self.no_params = true;
+        self
+    }
+
     /// Do not display the function return type.
-    pub no_return_type: bool,
+    pub fn no_return_type(mut self) -> Self {
+        self.no_return_type = true;
+        self
+    }
 }
 
 /// A `Symbol` which owns the underlying storage for the mangled name.
@@ -251,6 +268,9 @@ pub enum DemangleNodeType {
     NestedName,
     /// Entering a <special-name> production that is a vtable.
     VirtualTable,
+    /// Additional values may be added in the future. Use a
+    /// _ pattern for compatibility.
+    __NonExhaustive,
 }
 
 /// Sink for demangled text that reports syntactic structure.

tests/tests.rs

@@ -87,7 +87,7 @@ macro_rules! demangles_no_param_and_no_return_type {
     ( $name:ident , $mangled:expr , $demangled:expr ) => {
         #[test]
         fn $name() {
-            let options = DemangleOptions { no_params: true, no_return_type: true };
+            let options = DemangleOptions::new().no_params().no_return_type();
             assert_demangles_as($mangled, $demangled, Some(options));
         }
     };
@@ -100,7 +100,7 @@ macro_rules! demangles_no_return_type {
     ( $name:ident , $mangled:expr , $demangled:expr ) => {
         #[test]
         fn $name() {
-            let options = DemangleOptions { no_params: false, no_return_type: true };
+            let options = DemangleOptions::new().no_return_type();
             assert_demangles_as($mangled, $demangled, Some(options));
         }
     };
@@ -113,7 +113,7 @@ macro_rules! demangles_no_param {
     ( $name:ident , $mangled:expr , $demangled:expr ) => {
         #[test]
         fn $name() {
-            let options = DemangleOptions { no_params: true, no_return_type: false };
+            let options = DemangleOptions::new().no_params();
             assert_demangles_as($mangled, $demangled, Some(options));
         }
     };